text:
Android 11 tablet cannot connect to WiFi (saved; obtaining IP adrress)
I got a new Thomson Teo 13.3 Android 11 tablet (I started from factory defaults, it is brand new). I made a new Wi-Fi network on my NETGEAR WAX202 router, let's call its SSID "MyNetwork2", and had this tablet connect to it. It spins under "obtaining IP address" for a while; and then says "Saved" and that's all it shows.
I have 5 devices on my home network connected to the same router, and they work without a problem - although they are connected to a different Wi-Fi network. To test, I had my LineageOS 17 Samsung smartphone connect to this "MyNetwork2" - no problem whatsoever. So it is not the router, I imagine.
I found that Android 11 introduced some changes that may break WiFi network connectivity. Some of the articles I read:
Connecting Android 11+ devices to WPA/WPA2/WPA3/Enterprise SSID

Since Android 11 Security Enhancement released in December 2020, this has changed and as a result, you cannot skip the certificate validation.

PSA: Android 11 will no longer let you insecurely connect to enterprise WiFi networks

The problem that many users will come across after they update to Android 11* is that the "Do Not Validate" option under the "CA certificate" dropdown has been removed

Although that probably does not apply to me, because I do not use an enterprise network.
Eventually I also found:
Wi-Fi connection issues with the Xiaomi Mi A2

he had enabled WPA alongside WPA2 on the AP. They also confirmed that this wasn’t something I could’ve done myself, as there is no relevant option in the "user-facing" part of the configuration panel. ...

... which in turn leads wpa_supplicant to ignore the fact that there’s a MBO/OCE tag (which is, of course, still present) despite the AP not supporting PMF as reported in the RSN IE, and just use the WPA IE to choose the needed ciphers

I don't understand half of the words here, but I tried disabling dual frequencies on the WiFi network, and adding both WPA and WPA2 - and of course, this didn't work either.
Anyways, I tried to obtain a logcat during the connection attempts, when the WiFi network is in this state:

I tried to grep only for relevant stuff:
$ grep -i 'wifi\|wpa\|conn\|net' ~/Desktop/logcat2
06-29 10:24:30.387   413  4727 I WifiService: startScan uid=1000
06-29 10:24:30.822   413  4727 I WifiService: startScan uid=1000
06-29 10:24:31.852   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:34.867   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:35.820   413  4727 D WifiNl80211Manager: Scan result ready event
06-29 10:24:35.820   413  4727 D WifiNative: Scan result ready event
06-29 10:24:35.839   413   505 D WificondScannerImpl: Filtering out 2 scan results.
06-29 10:24:35.859   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:35.907  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:24:37.784   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:37.883  3892  3892 I wpa_supplicant: wlan0: CTRL-EVENT-DISCONNECTED bssid=37:XX:XX:XX:XX:e2 reason=3 locally_generated=1
06-29 10:24:37.892   326   326 I wificond: Regulatory domain changed
06-29 10:24:37.893   413   433 I EthernetTracker: interfaceLinkStateChanged, iface: wlan0, up: false
06-29 10:24:37.898   326   326 I wificond: 2.4Ghz frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472
06-29 10:24:37.901   326   326 I wificond: 5Ghz non-DFS frequencies:
06-29 10:24:37.901   326   326 I wificond: 5Ghz DFS frequencies:
06-29 10:24:37.901   326   326 I wificond: 6Ghz frequencies:
06-29 10:24:37.902   326   326 I wificond: Regulatory domain changed to country: ES
06-29 10:24:37.909   326   326 I wificond: 2.4Ghz frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472
06-29 10:24:37.909   326   326 I wificond: 5Ghz non-DFS frequencies:
06-29 10:24:37.909   326   326 I wificond: 5Ghz DFS frequencies:
06-29 10:24:37.909   326   326 I wificond: 6Ghz frequencies:
06-29 10:24:37.920   413   501 W LastMileLogger: Failed to stop event tracing: /sys/kernel/debug/tracing/instances/wifi/tracing_on: open failed: ENOENT (No such file or directory)
06-29 10:24:37.921   413   501 W LastMileLogger: Failed to read event trace: /sys/kernel/debug/tracing/instances/wifi/trace
06-29 10:24:37.929  3892  3892 I wpa_supplicant: wlan0: CTRL-EVENT-REGDOM-CHANGE init=CORE type=WORLD
06-29 10:24:37.949  3892  3892 I wpa_supplicant: wlan0: CTRL-EVENT-REGDOM-CHANGE init=USER type=COUNTRY alpha2=ES
06-29 10:24:37.952   413   501 D WifiCountryCode: Reading country code from telephony
06-29 10:24:37.963   413   501 D WifiCountryCode: Set telephony country code to:
06-29 10:24:37.965   413   501 D WifiCountryCode: updateCountryCode to null
06-29 10:24:37.965   413   501 D WifiClientModeImpl: Start Disconnecting Watchdog 23
06-29 10:24:37.968   413   501 I WifiClientModeImpl: Keep PMK cache for network disconnection reason 3
06-29 10:24:37.969   413   501 E WifiVendorHal: stopRssiMonitoring(l.2100) failed {.code = ERROR_NOT_AVAILABLE, .description = }
06-29 10:24:37.975   413   501 V WifiClientModeImpl: stopIpClient IpClientWithPreConnection: false
06-29 10:24:37.975   413   501 V WifiClientModeImpl: java.lang.Throwable
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.stopIpClient(ClientModeImpl.java:1069)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.stopDhcpSetup(ClientModeImpl.java:1084)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.handleNetworkDisconnect(ClientModeImpl.java:2761)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.access$5400(ClientModeImpl.java:163)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl$ConnectModeState.processMessage(ClientModeImpl.java:4290)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.processMsg(StateMachine.java:992)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.handleMessage(StateMachine.java:809)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at android.os.Handler.dispatchMessage(Handler.java:106)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at android.os.Looper.loop(Looper.java:223)
06-29 10:24:37.975   413   501 V WifiClientModeImpl:    at android.os.HandlerThread.run(HandlerThread.java:67)
06-29 10:24:37.977   413   506 D ConnectivityService: [122 WIFI] EVENT_NETWORK_INFO_CHANGED, going from UNKNOWN to DISCONNECTED
06-29 10:24:37.977   413   506 D ConnectivityService: [122 WIFI] disconnected, was satisfying 0
06-29 10:24:37.997   413   501 I WifiClientModeImpl: disconnectedstate enter
06-29 10:24:37.999   413   501 E WifiScoringParams: Invalid frequency(-1), using 5G as default rssi array
06-29 10:24:38.006   413   501 V WifiClientModeImpl: stopIpClient IpClientWithPreConnection: false
06-29 10:24:38.006   413   501 V WifiClientModeImpl: java.lang.Throwable
06-29 10:24:38.006   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.stopIpClient(ClientModeImpl.java:1069)
06-29 10:24:38.006   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.access$4200(ClientModeImpl.java:163)
06-29 10:24:38.006   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl$DisconnectedState.processMessage(ClientModeImpl.java:5686)
06-29 10:24:38.006   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.processMsg(StateMachine.java:992)
06-29 10:24:38.006   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.handleMessage(StateMachine.java:809)
06-29 10:24:38.006   413   501 V WifiClientModeImpl:    at android.os.Handler.dispatchMessage(Handler.java:106)
06-29 10:24:38.006   413   501 V WifiClientModeImpl:    at android.os.Looper.loop(Looper.java:223)
06-29 10:24:38.006   413   501 V WifiClientModeImpl:    at android.os.HandlerThread.run(HandlerThread.java:67)
06-29 10:24:38.009   413   501 I WifiClientModeImpl: Keep PMK cache for network disconnection reason 3
06-29 10:24:38.013   413   501 D WifiNetworkAgent: NetworkAgent: NetworkAgent channel lost
06-29 10:24:38.030   413   506 D ConnectivityService: NetReassign [no changes]
06-29 10:24:39.388   413  3531 D WifiNl80211Manager: Scan result ready event
06-29 10:24:39.388   413  3531 D WifiNative: Scan result ready event
06-29 10:24:39.431   413   505 D WificondScannerImpl: Filtering out 7 scan results.
06-29 10:24:39.447   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:39.475  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:24:40.391   413  4727 I WifiService: startScan uid=1000
06-29 10:24:40.827   413  4727 I WifiService: startScan uid=1000
06-29 10:24:41.776   413  4727 D WifiNl80211Manager: Scan result ready event
06-29 10:24:41.776   413  4727 D WifiNative: Scan result ready event
06-29 10:24:41.810   413   505 D WificondScannerImpl: Filtering out 4 scan results.
06-29 10:24:41.820   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:41.860  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:24:42.197   413  4727 I WifiService: connect uid=1000
06-29 10:24:42.208   413   501 D WifiConfigManager: Enable disabled network: "MyNetwork2" num=0
06-29 10:24:42.251   413   501 D WifiConfigStore: Writing to stores completed in 18 ms.
06-29 10:24:42.256   413   501 D WifiClientModeImpl: connectToUserSelectNetwork netId 5, uid 1000, forceReconnect = false
06-29 10:24:42.266   413   501 D WifiClientModeImpl: CMD_START_CONNECT  my state DisconnectedState nid=5 roam=false
06-29 10:24:42.310   413   501 D WifiClientModeImpl: No changes in MAC address
06-29 10:24:42.314   413   501 W LastMileLogger: Failed to open free_buffer pseudo-file: /sys/kernel/debug/tracing/instances/wifi/free_buffer: open failed: ENOENT (No such file or directory)
06-29 10:24:42.316   413   501 I WifiClientModeImpl: Connecting with 7a:f8:f8:9e:da:fc as the mac address
06-29 10:24:42.317   326   326 W wificond: Scan is not started. Ignore abort request
06-29 10:24:42.319   413   501 D SupplicantStaIfaceHal: connectToNetwork "MyNetwork2"WPA_PSK
06-29 10:24:42.319   413   501 D SupplicantStaIfaceHal: Network is already saved, but need to update BSSID.
06-29 10:24:42.334  3892  3892 I wpa_supplicant: wlan0: SME: Trying to authenticate with 37:XX:XX:XX:XX:e2 (SSID='MyNetwork2' freq=2472 MHz)
06-29 10:24:42.454  3892  3892 I wpa_supplicant: wlan0: Trying to associate with 37:XX:XX:XX:XX:e2 (SSID='MyNetwork2' freq=2472 MHz)
06-29 10:24:42.560   413   433 I EthernetTracker: interfaceLinkStateChanged, iface: wlan0, up: true
06-29 10:24:42.563  3892  3892 I wpa_supplicant: wlan0: Associated with 37:XX:XX:XX:XX:e2
06-29 10:24:42.568  3892  3892 I wpa_supplicant: wlan0: WPA: RX message 1 of 4-Way Handshake from 37:XX:XX:XX:XX:e2 (ver=2)
06-29 10:24:42.572  3892  3892 I wpa_supplicant: wlan0: WPA: Sending EAPOL-Key 2/4
06-29 10:24:42.572  3892  3892 I wpa_supplicant: wlan0: CTRL-EVENT-SUBNET-STATUS-UPDATE status=0
06-29 10:24:42.583  3892  3892 I wpa_supplicant: wlan0: WPA: RX message 3 of 4-Way Handshake from 37:XX:XX:XX:XX:e2 (ver=2)
06-29 10:24:42.583  3892  3892 I wpa_supplicant: wlan0: WPA: Sending EAPOL-Key 4/4
06-29 10:24:42.607  3892  3892 I wpa_supplicant: wlan0: WPA: Key negotiation completed with 37:XX:XX:XX:XX:e2 [PTK=CCMP GTK=TKIP]
06-29 10:24:42.607  3892  3892 I wpa_supplicant: wlan0: CTRL-EVENT-CONNECTED - Connection to 37:XX:XX:XX:XX:e2 completed [id=0 id_str=%7B%22configKey%22%3A%22%5C%22MyNetwork2%5C%22WPA_PSK%22%2C%22creatorUid%22%3A%221000%22%7D]
06-29 10:24:42.612   413   433 I EthernetTracker: interfaceLinkStateChanged, iface: wlan0, up: true
06-29 10:24:42.629   413   501 D ConnectivityService: registerNetworkAgent NetworkAgentInfo{ ni{[type: WIFI[], state: UNKNOWN/IDLE, reason: (unspecified), extra: , failover: false, available: true, roaming: false]}  network{123}  nethandle{531686674445}  lp{{InterfaceName: wlan0 LinkAddresses: [ ] DnsAddresses: [ ] Domains: null MTU: 0 Routes: [ ]}}  nc{[ Transports: WIFI Capabilities: NOT_METERED&INTERNET&NOT_RESTRICTED&TRUSTED&NOT_VPN&NOT_ROAMING&FOREGROUND&NOT_CONGESTED&NOT_SUSPENDED LinkUpBandwidth>=1048576Kbps LinkDnBandwidth>=1048576Kbps OwnerUid: 1000 SSID: "MyNetwork2" RequestorUid: -1 RequestorPackageName: null]}  Score{20}  everValidated{false}  lastValidated{false}  created{false} lingering{false} explicitlySelected{true} acceptUnvalidated{false} everCaptivePortalDetected{false} lastCaptivePortalDetected{false} partialConnectivity{false} acceptPartialConnectivity{false} clat{mBaseIface: null, mIface: null, mState: IDLE} }
06-29 10:24:42.663   413   506 D ConnectivityService: [123 WIFI] EVENT_NETWORK_INFO_CHANGED, going from UNKNOWN to UNKNOWN
06-29 10:24:42.680   413   501 V WifiClientModeImpl: stopIpClient IpClientWithPreConnection: false
06-29 10:24:42.680   413   501 V WifiClientModeImpl: java.lang.Throwable
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.stopIpClient(ClientModeImpl.java:1069)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.stopDhcpSetup(ClientModeImpl.java:1084)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.startIpClient(ClientModeImpl.java:6535)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.access$6800(ClientModeImpl.java:163)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl$ObtainingIpState.enter(ClientModeImpl.java:5132)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.invokeEnterMethods(StateMachine.java:1037)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.performTransitions(StateMachine.java:879)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.handleMessage(StateMachine.java:819)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at android.os.Handler.dispatchMessage(Handler.java:106)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at android.os.Looper.loop(Looper.java:223)
06-29 10:24:42.680   413   501 V WifiClientModeImpl:    at android.os.HandlerThread.run(HandlerThread.java:67)
06-29 10:24:42.693   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:42.717   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:42.741   413   506 D ConnectivityService: NetReassign [no changes]
06-29 10:24:42.756  3386  3386 E PreferenceGroup: Found duplicated key: "StandardWifiEntry:MyNetwork2,2". This can cause unintended behaviour, please use unique keys for every preference.
06-29 10:24:42.808   245   393 E Netd    : no such netId 123
06-29 10:24:42.832   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:45.737   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:48.754   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:50.442   413  4727 I WifiService: startScan uid=1000
06-29 10:24:50.465   326   326 E wificond: NL80211_CMD_TRIGGER_SCAN failed: Device or resource busy
06-29 10:24:50.466   413   505 E WificondScannerImpl: Failed to start scan, freqs=null
06-29 10:24:50.469   413   501 E WifiScanRequestProxy: Scan failure received. reason: -1,description: Scan failed
06-29 10:24:50.523  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:24:50.836   413  4727 I WifiService: startScan uid=1000
06-29 10:24:50.865   413   505 E WificondScannerImpl: Failed to start scan, freqs=null
06-29 10:24:50.869   413   501 E WifiScanRequestProxy: Scan failure received. reason: -1,description: Scan failed
06-29 10:24:50.933  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:24:51.767   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:50.864   326   326 E wificond: NL80211_CMD_TRIGGER_SCAN failed: Device or resource busy
06-29 10:24:54.789   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:24:57.806   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:25:00.454   413  6577 I WifiService: startScan uid=1000
06-29 10:25:00.716   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:25:00.844   413  6577 I WifiService: startScan uid=1000
06-29 10:25:04.849   413  6577 E WifiThreadRunner: WifiThreadRunner.call() timed out!
06-29 10:25:04.849   413  6577 E WifiThreadRunner: java.lang.Throwable: Stack trace:
06-29 10:25:04.849   413  6577 E WifiThreadRunner:  at com.android.server.wifi.WifiThreadRunner.call(WifiThreadRunner.java:80)
06-29 10:25:04.849   413  6577 E WifiThreadRunner:  at com.android.server.wifi.WifiServiceImpl.startScan(WifiServiceImpl.java:497)
06-29 10:25:04.849   413  6577 E WifiThreadRunner:  at android.net.wifi.IWifiManager$Stub.onTransact(IWifiManager.java:718)
06-29 10:25:04.849   413  6577 E WifiThreadRunner:  at android.os.Binder.execTransactInternal(Binder.java:1154)
06-29 10:25:04.849   413  6577 E WifiThreadRunner:  at android.os.Binder.execTransact(Binder.java:1123)
06-29 10:25:05.967  3892  3892 I wpa_supplicant: wlan0: CTRL-EVENT-DISCONNECTED bssid=37:XX:XX:XX:XX:e2 reason=3 locally_generated=1
06-29 10:25:05.970   413   433 I EthernetTracker: interfaceLinkStateChanged, iface: wlan0, up: false
06-29 10:25:05.971   326   326 I wificond: Regulatory domain changed
06-29 10:25:05.973   413  3531 D WifiNl80211Manager: Scan result ready event
06-29 10:25:05.973   413  3531 D WifiNative: Scan result ready event
06-29 10:25:05.980   413   501 W LastMileLogger: Failed to stop event tracing: /sys/kernel/debug/tracing/instances/wifi/tracing_on: open failed: ENOENT (No such file or directory)
06-29 10:25:05.982   413   501 W LastMileLogger: Failed to read event trace: /sys/kernel/debug/tracing/instances/wifi/trace
06-29 10:25:05.985   326   326 I wificond: 2.4Ghz frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472
06-29 10:25:05.987   326   326 I wificond: 5Ghz non-DFS frequencies:
06-29 10:25:05.987   326   326 I wificond: 5Ghz DFS frequencies:
06-29 10:25:05.987   326   326 I wificond: 6Ghz frequencies:
06-29 10:25:05.987   326   326 I wificond: Regulatory domain changed to country: ES
06-29 10:25:05.989   413   501 D WifiCountryCode: Reading country code from telephony
06-29 10:25:05.989  3892  3892 I wpa_supplicant: wlan0: CTRL-EVENT-REGDOM-CHANGE init=CORE type=WORLD
06-29 10:25:05.992   413   501 D WifiCountryCode: Set telephony country code to:
06-29 10:25:05.992   326   326 I wificond: 2.4Ghz frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472
06-29 10:25:05.993   326   326 I wificond: 5Ghz non-DFS frequencies:
06-29 10:25:05.993   413   501 D WifiCountryCode: updateCountryCode to null
06-29 10:25:05.993   326   326 I wificond: 5Ghz DFS frequencies:
06-29 10:25:05.993   326   326 I wificond: 6Ghz frequencies:
06-29 10:25:05.993   413   501 D WifiClientModeImpl: Start Disconnecting Watchdog 24
06-29 10:25:05.994  3892  3892 I wpa_supplicant: wlan0: CTRL-EVENT-REGDOM-CHANGE init=USER type=COUNTRY alpha2=ES
06-29 10:25:05.999   413   501 I WifiClientModeImpl: Keep PMK cache for network disconnection reason 3
06-29 10:25:06.001   413   501 E WifiVendorHal: stopRssiMonitoring(l.2100) failed {.code = ERROR_NOT_AVAILABLE, .description = }
06-29 10:25:06.007   413   505 D WificondScannerImpl: Filtering out 1 scan results.
06-29 10:25:06.007   413   501 V WifiClientModeImpl: stopIpClient IpClientWithPreConnection: false
06-29 10:25:06.007   413   501 V WifiClientModeImpl: java.lang.Throwable
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.stopIpClient(ClientModeImpl.java:1069)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.stopDhcpSetup(ClientModeImpl.java:1084)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.handleNetworkDisconnect(ClientModeImpl.java:2761)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.access$5400(ClientModeImpl.java:163)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl$ConnectModeState.processMessage(ClientModeImpl.java:4290)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.processMsg(StateMachine.java:992)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.handleMessage(StateMachine.java:809)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at android.os.Handler.dispatchMessage(Handler.java:106)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at android.os.Looper.loop(Looper.java:223)
06-29 10:25:06.007   413   501 V WifiClientModeImpl:    at android.os.HandlerThread.run(HandlerThread.java:67)
06-29 10:25:06.021   413   506 D ConnectivityService: [123 WIFI] EVENT_NETWORK_INFO_CHANGED, going from UNKNOWN to DISCONNECTED
06-29 10:25:06.021   413   506 D ConnectivityService: [123 WIFI] disconnected, was satisfying 0
06-29 10:25:06.029   413   501 I WifiClientModeImpl: disconnectedstate enter
06-29 10:25:06.035   413   501 E WifiScoringParams: Invalid frequency(-1), using 5G as default rssi array
06-29 10:25:06.040  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:25:06.042   413   501 V WifiClientModeImpl: stopIpClient IpClientWithPreConnection: false
06-29 10:25:06.042   413   501 V WifiClientModeImpl: java.lang.Throwable
06-29 10:25:06.042   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.stopIpClient(ClientModeImpl.java:1069)
06-29 10:25:06.042   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl.access$4200(ClientModeImpl.java:163)
06-29 10:25:06.042   413   501 V WifiClientModeImpl:    at com.android.server.wifi.ClientModeImpl$DisconnectedState.processMessage(ClientModeImpl.java:5686)
06-29 10:25:06.042   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.processMsg(StateMachine.java:992)
06-29 10:25:06.042   413   501 V WifiClientModeImpl:    at com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.handleMessage(StateMachine.java:809)
06-29 10:25:06.042   413   501 V WifiClientModeImpl:    at android.os.Handler.dispatchMessage(Handler.java:106)
06-29 10:25:06.042   413   501 V WifiClientModeImpl:    at android.os.Looper.loop(Looper.java:223)
06-29 10:25:06.042   413   501 V WifiClientModeImpl:    at android.os.HandlerThread.run(HandlerThread.java:67)
06-29 10:25:06.042   413   501 I WifiClientModeImpl: Keep PMK cache for network disconnection reason 3
06-29 10:25:06.049   413   501 D WifiNetworkAgent: NetworkAgent: NetworkAgent channel lost
06-29 10:25:06.055   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:25:06.073   413   506 D ConnectivityService: NetReassign [no changes]
06-29 10:25:06.137  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:25:07.389   413  4727 D WifiNl80211Manager: Scan result ready event
06-29 10:25:07.389   413  4727 D WifiNative: Scan result ready event
06-29 10:25:07.411   413   505 D WificondScannerImpl: Filtering out 5 scan results.
06-29 10:25:07.425   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:25:07.461  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:25:10.475   413  4727 I WifiService: startScan uid=1000
06-29 10:25:11.845   413  4727 D WifiNl80211Manager: Scan result ready event
06-29 10:25:11.845   413  4727 D WifiNative: Scan result ready event
06-29 10:25:11.860   413   505 D WificondScannerImpl: Filtering out 2 scan results.
06-29 10:25:11.872   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:25:11.926  1020  1754 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl
06-29 10:25:14.866   413  4727 I WifiService: startScan uid=1000
06-29 10:25:16.043   413   501 D WifiConfigStore: Writing to stores completed in 13 ms.
06-29 10:25:16.251   413  3531 D WifiNl80211Manager: Scan result ready event
06-29 10:25:16.251   413  3531 D WifiNative: Scan result ready event
06-29 10:25:16.267   413   505 D WificondScannerImpl: Filtering out 3 scan results.
06-29 10:25:16.279   413   501 E WifiVendorHal: getWifiLinkLayerStats_1_3_Internal(l.973) failed {.code = ERROR_UNKNOWN, .description = unknown error}
06-29 10:25:16.343  1020  1178 I ChimeraSrvcProxy: NullBinder for android.net.action.RECOMMEND_NETWORKS triggering remote TransactionTooLargeException due to Service without Chimera impl

I am unable to make sense of the above logs. They are nothing short of gibberish to an end-user trying to debug their problem.
So, would anyone have an idea about what is wrong here - and what should I do to get WiFi connection with this tablet on this router and network work?

The router screenshot shows that you have enabled WPA +WPA2 in "security options". Besides the fact that this is insecure and totally unnecessary as every device released in the last 15 years support WPA2 it is exactly the problematic situation you quoted in your question.

Thanks @Robert - well, the network was originally in WPA2-Personal [AES] only, and it didn't work - which is why at first, I took the advice of the linked article and enabled both, which again did not help. My guess is, the tablet is incapable of handling 5 GHz, and that was apparently the problem - once I set the WIFi to 2.4 GHz only and WPA2-Personal [AES] only, then it could connect.

First of all, I found https://f-droid.org/packages/com.vrem.wifianalyzer/ - obviously, it had to be installed via adb install over USB, as I did not have WiFi.
But this program showed, that all this device can see, are networks in the 2.4 GHz range. So, I set my network to 5 GHz only - and suddenly, it was invisible to the tablet.
Then I thought, I should take a closer look at the specs of the tablet. Of course, there are no specs of the tablet to find easily.
Thankfully, I finally found something that looks more or less reasonable:
https://mobilespecs.net/tablet/THOMSON/Thomson_TEO_13P_T13P2BK32V2_32_GB_13.3_T13P2BK32V3.html

Processor model: A133
Processor family: Allwinner
Wi-Fi standards: 802.11b, 802.11g, Wi-Fi 4 (802.11n)
Top Wi-Fi standard: Wi-Fi 4 (802.11n)

Rather unfortunate (though expected), there is no mention of what WiFi chipset is being used; I found this: https://www.cnx-software.com/2020/10/31/allwinner-a133-tablet-processor-pairs-with-xr829-or-aw859a-wifi-bluetooth-chip/

the company also pairs A133 processor with its own wireless chips, either XR829 WiFI 4 and Bluetooth 4.2 chip, or AW859A dual-band 802.11ac WiFi 5 and Bluetooth 5 chip.

So, my guess is this device has an XR829 WiFi chipset. But never mind that.
If I look at https://www.rfwireless-world.com/Terminology/difference-between-wifi-6-and-wifi-5.html - they mention that WiFi 3 "supports 2.4 GHz and 5 GHz frequency bands", but there is no such mention for WiFi 4. So, I cannot really tell, if WiFi 4 in principle supports 5 GHz - but based on what the app above reported, I assumed that this WiFi chip cannot handle 5 GHz.
So, I just made these changes to my WiFi network, with respect to the screenshot posted above in OP:

Security options: back to WPA2-Personal [AES] only
Band: 2.4 GHz only

... and finally, it connected to the Wi-Fi.


text:
WhatsApp giving error message "unable to back up" (Google Drive)
My WhatsApp has been giving me trouble for a long time regarding backups. It started a couple of months ago when I pressed back up now and I received an error message saying "unable to back up". A little while later, my WhatsApp suddenly crashed and when I tried opening it, I received an additional error message saying

Something went wrong with your chat history, don't worry you can restore your chat history from backup. If you don't restore now you won't be able to restore later.

After pressing "backup now", it responds with "unable to retrieve old backup from Google drive."
I tried looking up different solutions and I did everything including, resetting the cache, disconnecting and reconnecting my Google account, turning off my phone, and playing around with every possible setting. I have plenty of storage on my device and Google Drive account and a great internet connection, so I had no idea where the problem was. The only solution that helped was when I switched my WhatsApp number to a different number. After that, I was able to back up to Google Drive normally as it should be. Unfortunately, I  had to reset my WhatsApp from new and start again which was really irritating, on the bright side I was able to do backups moving forward.
My WhatsApp has been working fine ever since yesterday when it gave me the same "unable to back up" error message I'm all too familiar with. Not surprisingly, the next day my WhatsApp crashed and the situation that happened a couple of months ago repeated itself.

Please help me understand what's wrong with my WhatsApp and if there are any solutions or fixes I can do. I've scoured the internet and I haven't found any solutions that have worked.
The problem now being when I press backup now I get an error message "unable to backup " in response. Any idea of what could be wrong/if some file is corrupt how to fix it?

Is your chats on the device now? I mean did you synced all the chats and media (that 2.5GB) on the phone offine? If so, make sure drive is updated. Then open Google Drive application, tap the hamburger menu, click Backups. Delete WhatsApp backup by clicking on the Delete backup option, then close the Google Drive app. Preferably reboot. And head to whatsapp and create a new backup. This will consume 2.5 cellular data if on mobile network.

Ahh, one of the gut-wrenching WhatsApp problems. Try below after you have tried all other options.

Change backup frequency to "never", under 'Back up to Google Drive".

Force stop WhatsApp.

Clear cache.

Remove Photos and Videos permission for WhatsApp.

Give said permission back to WhatsApp.

Open WhatsApp and change the backup frequency to whichever you prefer
under "Back up to Google Drive" (I set it to "daily").

Tap "Back up".

I believe this would definitely work. It did for me and many of my friends.

Normally when WhatsApp makes a backup, it makes a local backup too. You can find the local backup on your phone's memory or sd card under the WhatsApp folder. You should probably backup the backup so it doesn't get overwritten by a new backup, then you can turn off Google Drive backup and see if you can do "Backup now". It should then only make a local backup.
If that doesn't work you should try putting the local backup back. I am not sure what the cause could be, I would assume either your phone isn't authenticating with Google Drive properly or your Drive is full. Try logging off from Google and logging back in. There may be an issue with the data of WhatsApp itself. Sometimes clearing the cache helps but I can't guarantee what'll work and what not.
It looks like it managed to create a backup 16 days ago, so if nothing works you should still have a proper copy of your messages from everything before that date. Reinstalling WhatsApp should then give you the option to recover from Google Drive, but you will lose 16 days of chat history unless if you use the local backup.

I've disconnected my Google drive account from Whatsapp and tried doing just the internal backup again with no success. The error "unable to backup messages" still pops up. After taking a closer look at the files themselves I find that the media and backups folders actually do get backed up every time I press back up now, but not the database file. Is there any explanation for that and or a fix to the problem itself?

@Ktclmymlrk I would assume there is an error reading the database then, you may be able to try to rename the WhatsApp folder so it creates it from scratch. Otherwise something deeper you may want to try to restore from a working backup. It could be possible you can use adb logcat to see what errors it shows, that would give us a more detailed overview of what WhatsApp tries before it fails.

I'm not familiar with adb logcat, can you elaborate or explain how to do this. Also are there any third party apps/softwares I can use to backup Whatsapp. I've pretty much given up on trying to fix whatsapp, since I have no idea on how to even diagnose the problem.

@Ktclmymlrk Sorry for the late reply. I don't think there is any third party software that can backup WhatsApp since the data is in the app's private storage. You should try a file manager app and see if there is a WhatsApp folder on your internal storage or sd card. If there is, you should try to delete WhatsApp's data, but remember there might be a small chance that your messages can't be recovered. Normally when logging back in using the same phone number you can recover the chats from the local backup.

I did everything you said and it still gives me the "unable to back up messages" error whenever I press back up now. The issue isn't with my Google drive account because it doesn't even let me run an internal backup either. Is there any fix to this or a way to even debug the problem?

Well, I think the last resort would be to clear the cache or WhatsApps data. I suggest trying another method of backing up the app data. Samsung has things like smart switch, or Huawei has a built in backup app. If you have a backup already and are very sure it contains all the data you want you may try to clear the app data. If you really don't want to mess with your WhatsApp it may also be possible to modify the WhatsApp apk's app id and install a second clone of the app, or a third party WhatsApp client to try and see if you can restore your data, or leave WhatsApp and use the other client.

I don't have a Samsung or a Huawei so Is there another backup method I can try. The last resort would be to restart my WhatsApp again from scratch but I really don't want to lose the years of chats and messages I have, and who's to say the same error that happened to me won't happen again. Is there anyone who knows what's going on and can help me?

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


text:
Connection fails when receiving photos from Nintendo Switch
I am attempting to wirelessly send screenshots from my Nintendo Switch to my Asus Zenfone 8. However, when I try to scan the QR code to connect to my phone to my Switch I get a "Connection Failed" error. I tried manually connecting to my Switch in the wifi settings and navigating to "http://192.168.0.1/index.html", but the page was stuck on the loading screen in Firefox.
Why can't I transfer photos from my Switch to my Asus Zenfone 8?

You should first check your Wifi router, most routers deny Wifi-to-Wifi connections by default.

I think this option has the switch emulate a wifi hotspot jtself

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How to determine if an Android device is compromised with a rootkit?
How would you go about checking your smartphone for root level malware, including rootkits, if you cannot get direct access to smartphone partitions?
There's news almost monthly how cheap Android phones or even Android smart TVs contain malware. And then devices invariably stop being updated (some come without updates at all), and people continue to happily use them, while their e.g. Linux kernel is rife with local root exploits.

Hello. I've edited your question and removed the part concerning Google. We can't tell why Google did or does something. You are free to search  Google's press releases, its developers comments on various forums and so on to figure out the reason. It would all be opinions that we can provide (and a question that seeks opinions is off-topic here). I've therefore removed the off-topic part. Aside from that, you might get better suggestions at [security.se] than here.

I'm in secops and I don't know the answer other than trying to exploit a root vulnerability which is usually available for old unsupported devices. You've removed a very important part of the question which is "oem unlock erases user data". That's a way in, along with unlocking boot loader and using e.g magisk or/and TWRP but too often undesired for obvious reasons.

oem unlock does not erase user data - bootloader unlock does. this is for privacy protection. I don't believe in rootkits, simple factory reset will remove possible malware

Rootkit can remount the system partition in read write mode and plant whatever it desires.

no. dm-verity prevents that.

You seem to be right https://source.android.com/docs/security/features/verifiedboot but I wonder if Google can really enforce it on all Android vendors and then there's a question of ROMs which come with malware preinstalled by the OEM itself.

preinstalled malware by OEM is not malware. that's a opinion-based definition of malware. I don't know of any other method to check for other than analyzing the traffic. if you don't like it, don't use stock ROM

If the malware has modified system partition you can safely unlock bootloader - as user data erase does not modify system partition you can then simply access the malware for analyzing it. And if the ROM was infected with malware you can also unlock bootloader to get root access and extracting the firmware.


text:
Does a stock email app auto-update?
To clarify, two things:
1. I mean auto-updates to the app itself, not syncing to receive emails.
2. I'm not sure if there's a *difference, but I'm more interested in knowing about the stock apps/versions of stock apps that don't seem to have any way for you to manually update them yourself. For example, on my Galaxy S7 Edge (running Android 7.0), in the stock Email app, I can go into the Galaxy Apps store, or through the email app settings to the Galaxy Apps store to update the app; but on an Alcatel OneTouch Elevate I have (my previous phone)(running Android 5.1.1), there appears to be no way at all for me to update the stock Email app.
So, my question turns into: Do stock email apps, like the one on my Alcatel, auto-update? Does it perhaps get updated as part of the system update?
*by this, I kind of meant that I'm not really interested in knowing whether the stock email apps that you can manually update will also auto-update. So perhaps another form of the question is: If you can't update it, does it auto-update?

There is a global Auto Update option in Android 7.0 (possibly previous versions but I can't check now) which automatically updates all apps.
There is also a per-application setting. In case you have the global option off, then you can have that one enabled and it will still auto update. So be sure that both are off if you want the app not to auto-update.
By default, I believe the global option is on but that might depend on the phone.
For clarity, when an app is updated, we call that an update, when its data is updated, we call that a sync, such as downloading new emails as they arrive.
Stock apps are part of the system, so they will update when you accept a system update.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
I cant install a application!
I'm trying to install a 1-click root app but just the install button is broken. Cancel works, but not the install button.
Also this is the Android dialog box, not the webpage itself.
EDIT: Now I'm trying to test an app that i made but it wont let me install it...
Also I have no filter apps

The app you are trying to install can't root this phone. One-click root methods won't work in higher android version (5 > 7)

Im not using any filter apps

Check if you activate install from other than market, also check can you reinstall any of app. Also you may use other tools like King (Kingo) root.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
My mobile screen touches itself repeatedly(Ghost Touches)?
I have Swipe Elite Note android mobile phone.
My mobile screen touches itself repeatedly. I tink it might be a hardware issue.
However, it is working well today!
How can I confirm if it was an hardware issue or a software problem?

Boot into Safe Mode... Does the problem persist? If yes, probably hardware, if no, factory reset and try again.

Likely to be hardware but to confirm you could see if this behaviour persists in safe mode - of it doesn't, it may point to software ( you would need to check multiple times given that the problem seems random)

@beeshyams Is there any app using which I can disable that part of my mobile screen touch?

No but they're are questions here on how to that - search for them for possible ways


text:
Do phone's sync or back up their notes?
I have just got a replacement phone. I backed up all my data with google and GCloud, and then claimed on the insurance to get a new phone.
However after restoring all the data to my new phone, I have noticed the notes are missing.
I have:
ALL the tangible readable files from the old phone that can be transferred to a computer.
The system settings from the old phone, the messages, contacts, etc.
Whatever data google has synced.
The SD card from the old phone.
Unfortunately I do NOT physically have the old phone as the insurance has to take it to give me a new one.
Is there any way to get my notes back? Have they been stores anywhere I am unaware of?
The notes app is the app installed by default on my Huawei P9 Lite

This would be based on the "notes" app you were using, some do some don't. I always Google Keep so all notes are stored in the cloud. What app and does it show up in your Google account backup list?

How do I see the backup list?

@acejavelin (sorry forgot how to tag haven't used site for a while)

Go to your Google Dashboard  https://www.google.com/dashboard/b/0/ and find the section Android and open it then find your device, you will see a list of all apps that have data backed up to Google. I highly doubt your old Huawei backed up it's internal notes app there, but you can look. Note that all you can see is what apps have backed up data, you can't actually access that data without restoring it to the app.

@acejavelin it's not there, but thanks for the suggestion.

So then unless you have the old phone and can get into the app and export or save them somewhere or somehow, the data is probably lost.

@acejavelin I called Carphone Warehouse and they still had the phone, so they were able to give it to me temporarily and I was able to screenshot them and transfer them to the SD card. So I guess this is "solved" from my point of view.


text:
Can I schedule a night restore/wipe? Or other management solution
I (will shortly) have a small (5-10) android tablets for use in my school. I want them to automatically wipe clean at the end of each day (specifically, remove any user data, even more specifically, browsing history/downloads). I'd mostly likely have the devices locked down to just web browsing using surelock or similar.
How can I do this? Titanium backup doesn't seem to have a scheduled restore function.
Alternately, are there other management tools that would achieve a similar result?

There are two products in market which i found awesome :)
SureFox :  Kiosk Mode browser for Android Smartphones and Tablet which restricts user to browse only selected Websites, Which has many more options inside Browser Preferences For eg. Private Browsing and many More. try exploring this.
SureLock : You already Know about it ;)
You can try using SureFox on top of SureLock

Not sure if it's possible to do a factory reset with it but I know that Tasker is a great tool to automate things. You can try it for free first.

I don't want a factory reset (I need to maintain certain settings eg wifi credentials). I use tasker on my phone, but haven't found a function that does this.

So you want to delete a set of files from the sdcard then? Try python for android for instance, you can shedule a python script from within Tasker

That sounds to me like you'd need to root the phones and write a bash script to execute the SD card wipe and the browser cache wipe.  If you don't know how to write scripts, Stack Overflow is a good place to ask for help (the primary Stack Exchange site).  Script Manager is a good app for managing your scripts and when they execute (on boot would probably make the most sense, especially if you use Tasker to shut the machine down every night on a schedule).

You can delete the data and cache for each app one by one, from within the application settings, then wipe the sdcard.
But, if all you need to do in terms of setting up is a (short) wifi keys, then a factory reset might be best. It may be possible to bake your settings into the rom  e.g put your wifi keys in /system/etc/wifi/wifi_supplicant.conf . That example would allow wifi keys to survive a factory reset.
Any other solution I can think of would involve constantly (un)rooting , especially if you're talking about teenagers. Or, you could lock down root access with Superuser Elite  and if you were confident that nobody would be messing with adb, you might go that way.
There are "business solutions" out there, but that would be too much surely.


text:
How do I secure my Lenovo ThinkPad tablet against thieves when it doesn't have a Kensington lock?
The manual for the Lenovo ThinkPad doesn't say that it has a Kensington-like lock device on it, so are there any other ways for me to secure it against thieves?
I'd like to secure my tablet against the knobs that you can secure Kensington locks around. I know that Kensington locks aren't completely secure, but they can at least deter the vast majority of thieves.

I'd like to secure my tablet against the knobs that made me chuckle because, due to differences in culture and what-nots, "knob" is a slang for something else...

I believe your question is trying to ask 'Are there any laptop security devices out there that do not use a kensington lock slot?' The answer is, Yes.
To see a nice list of various types of locks that are available for notebooks and laptops, please see this website.
I in no way endorse this seller, however they are one of the few sites that seem to have a nice listing of many kensington-alternative locking devices for laptops. I am merely using it for informative purposes.


text:
Cannot install or update apps on LG G2x
My signficant other and I each have a T-Mobile-branded LG G2X P999.  An over-the-air update was recently released that upgrades the OS from 2.3.3 to 2.3.4.  She got the OTA update; I have not received it yet (and, given this problem, will refuse it until a solution is found).  Since the update, she can no longer install or update apps.  She gets the error (when updating Google Maps, for instance):

Error downloading "Maps".  There is insufficient space on the device.

This is happening even after uninstalling some apps (which can no longer be reinstalled due to the error.)  Internal storage has 248 MB used and 1.2 GB free.  The SD card has 603 MB used and 4.6 GB free.
Some people on the T-Mobile support discussion board discuss a hard reset being a solution for this issue.  I would prefer to avoid that solution if possible, simply because it is a hassle and because we do not know what data she might end up losing.
How can she fix this issue?  Is there a way to fix it besides a hard reset?

I had the same problem with my wife's phone (LG G2x P999). Unfortunately you're going to have to master reset....
If it doesn't work from the settings, then reset manually (hold power button and volume down till you see the Android guy then let go) after that your phone will be reset and the downloading issue will stop. Read through these steps prior to resetting to ensure you don't lose anything you don't wanna....hope this helped you
http://support.t-mobile.com/docs/DOC-2521
should be the 5th link down where it says preparing for master reset


text:
CyanogenMod 7 - can I hide the status bar on the lockscreen?
I am using a Google Nexus One and have just flashed CyanogenMod 7 onto it.  I noticed that the lockscreen shows the status bar on it, as shown on the image with this post.
Is there a way to hide the status bar on the lockscreen?  You can see what I am trying to achieve in this case, which is a lockscreen that only displays the wallpaper (CyanogenMod gesture to unlock).  I have been able to hide the sliders as well through the CyanogenMod settings but could not find a way to hide the status bar when the lockscreen is active.

(Click image to enlarge)

Switch to custom lockscreens. Many provide a way to hide status bar. I use WidgetLocker Lockscreen which supports this feature.

My main reason for sticking with CM7 is the gesture based lock screen.  Does WidgetLocker Lockscreen allow for gestures/drawings to unlock?


text:
Can I set up my Galaxy Tab to boot from the external SD card?
I'm having some issues with my Samsung Galaxy Tab, model SCH-I800 (VZW).
It started giving me a reboot loop one day (completely stock at this point). I've flashed ROMs and whatnot in the past, so I thought this would be an easy fix.
Based on the symptoms that this thing is exhibiting, I believe that the internal flash storage has gone bad. However, I do not have the desire to take this thing part and desolder the chip. So how do I get this Tab to boot off the external SD card? I've tried everything google has to offer thus far:

Manually (and correctly) partitioned SD card.
Edited /etc/fstab in addition to vold.fstab.
Flashed numerous ROMs.
Data/cache wipe in CWM 3.0.0.5 (for some reason, the newest version won't flash).

Running ls /dev/block in an adb shell shows mmcblk0, mmcblk1p1, and mmcblk1p2. For some reason, after every reboot, mount /sdcard throws an error that references mmcblk0 instead of mmcblk1. I am at my wit's end. I think /etc/fstab isn't sticking after reboot, but I honestly don't know. My knowledge of *nix-based systems is somewhat limited.
Is there any way for me to get this to boot from the external SD card?

Have you looked at trying a stock odin flash first to fix it? You will have to modify the boot.img to boot from sdcard, which still runs from internal NAND, and there is nothing you can do about that

Unless I am misunderstanding you, it isn't the internal NAND that is messed up. It is the internal flash storage that the Tab mounts as /sdcard by default (it's confusing, the internal storage is mounted as /sdcard and the external sd card is mounted as /sdcard/external). Any time I flash with odin, it hangs on hidden.fs. I've tried two stock ROMs (same ROM, different sources) and a few modified ROMs. I am not sure how to modify boot.img but I will certainly google it.
Thanks in advance. Let me know if I can provide more information.

Not totally sure on the workings of ODIN, but I know that devs make custom odin files... can you maybe try one without the hidden.fs? Like have it removed from the archive before flashing? Maybe once booted you could format the internal flash memory in Android itself or in a revocery (CWM, TWRP, whatever)

I've tried manually removing hidden.fs and just picking individual files from the archive to flash with heimdall. Nothing has worked so far. Also I can't mount mmcblk0 (internal storage) to format it. It throws an error when I try. Thanks though.

Sorry but it's not possible to boot from an external sd card since when the phone powers up the processor start to execute code at a fixed adress in the nand, and you can't change that.


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Prevent play store from showing me updates on an application installed through another store
Recently Amazon disabled all in-app purchases from their apps distributed through the Play Store.
As I'm a frequent user of the kindle app, and not a fan on switching to my browser instead of in-app purchases, I've opted to install Amazon AppStore and through it the Kindle for Android app.
Now, though, the Play Store always displays an update available for the Kindle for Android app.
What I would like, is a way to tell the play store not to try and manage this application.
I've already disabled automatic updates, but the issue with this is that every time I touch "Update all applications" I have to deal with a popup to confirm I want to ignore KFA updates.
It's not that big of a deal, but i'm wary of mistake on my part later down the line.
EDIT: My phone is not currently rooted, and the manufacturer enforces a factory reset to unlock the bootloader. As it stands I'd prefer not to have to root the phone (Xiaomi Mi 9T Pro)

In the switching process was the Kindle app always installed? If yes I would try to uninstall it and then reinstall it via Amazon app store. If you have adb enabled you can do adb uninstall -k com.amazon.kindle to uninstall the app but keep the data.

No, I uninstalled it from the application list of the OS. Then installed it from the Amazon AppStore. I kind of suspect, that they are using the same package id and signature on the two stores.

With root access via magisk, you can use this module to exclude an app from play store updates
https://github.com/yuk7/playstore-excl-upd

Thanks for the option, but my phone is not currently rooted, and the manufacturer enforces a factory reset to unlock the bootloader. As it stands I'd prefer not to have to root the phone, I'll add that to the question


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Frequency band mofications for Samsung Galaxy S4
I recently purchased a used, unlocked Samsung Galaxy S4 SGH-I337M (for the particular model see here). The phones native bands don't include the 1700/2100 AWS required by the cell phone provider (WIND mobile). However, the phone is able to get both talk and data as desired. The previous owner told me that he modified the phone to allow these bands.
I'd like to know

Why was this possible? Is it because the phone has the bands but Samsung suppressed them or is the phone being hoodwinked into working without having both bands?
Whether there is a chance a firmware update or factory reset will undo this feature?

Background: I'm a bit familiar with unlocking AWS bands using qcn files

Ok then, let me begin by answering in order

This is possible if the previous owner flashed their own hybrid modem onto their phone, which allows phones that are physically able to use a  certain band (1700/2100) in your case, but the company does not allow it on their stock modem (for many different reasons). The hybrid modem basically overwrites the old modem that in short, says to the phone, "Hey, these are the only bands you can use", while a hybrid modem tells the phone, "Go crazy", and unlocks all or certain bands at a cost of battery life (more bands, more battery is needed to power it.)
Most probably, yes.  A factory will wipe out the hybrid modem and replace it with the stock. So only update if you have a copy of the hybrid modem, and know how to flash it. (ODIN)

I hope this answers it for you.

Thanks for your response. Do you know how flashing a hybrid modem differentiates from unlocking bands using a qcn file (if at all)?

Yes. A hybrid modem rewrites the already existing modem on the phone, While a QCN file is most likely a (modified)backup file for Qualcomm device for UMTS-based phones.

I do not know the specifics on how the flashing of a hybrid modem differentiates from QCN files, but a hybrid modem can usually be used for ALL phones. While CQN is only for Qualcomm Phones.


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Android 4.0.3 has virtual keyboard with Y key in wrong place?
Why the virtual keyboard of Android 4.0 has a different qwerty virtual keyboard? It seems the Y is in the wrong place.
Is it some configuration? Where it is?

Screenshots (click images for larger variants)

Are the Y and Z keys switched?
It sounds as if you have the wrong language set for your keyboard (or your system, as it defaults to the systems language). Some European keyboard layouts, possibly German, have a QWERTZ layout instead.
Settings > Language & input > Android keyboard (Settings icon) > Input languages

Yes, Y instead of Z. So it already are in English (USA) input language as default. I reset the device but without success...

Hhhmm, curious. If it is a QWERTZ layout then there are likely to be several other differences, particularly with punctuation. What are the keys to the right of the L? Also, what exactly does it state as the input language? For instance, it should state "English (US)", not "English (USA)" as you mention. And the language for the device should be stated as "English (United States)".

I added the images.

Ah, I see from the screenshots that you are (were) using the "Samsung keypad" - this isn't the default "Android keyboard" that comes as part of ICS. The "Android keyboard" should also state (directly beneath it) which language it is configured for (which the "Samsung keypad" does not appear to show.)

Yes, I think is the Samsung German Layout. I can't replace it, so I installed Hacker's Keyboard from google play.

Had the same problem. Go to Settings -> Applications -> Manage applications -> All -> Your keypad (Samsung Keypad for me). Force stop and then clear data. Solved the issue for me.

I solved installing Hackers keyboard of Android Market.

This is not a solution. BTW, there are many virtual keyboards for ICS.

I had the same issue, and solved it by doing this:

Open keyboard and click the settings icon
Click input language
Uncheck any languages you don't need

This fixed the problem for me.

I solved this problem here in the UK by changing the language to English (Ireland) keyboard and it was fine, the mic icon said EN again too, not DE which it had changed itself to. After that, I changed back to the UK and it was fine too. Weird glitch.

Open Settings
Go to "Locale & Text"
Then "Samsung keypad"
Then "Input languages"
Only tick mark on English US (note: unmark all other languages if it's ticked).

Hold the spacebar in and swipe left or right to quickly change languages you have it set to English Canadian atm.

I was having the same issue with the W and Z being in the wrong place and was going into the keyboard settings under my phone setting and still was not finding how to fix it. Doing what was suggested here, it did indeed change the letters but I was using Swift keyboard, so when I was changing my phones keyboard, it was not changing the Swift keyboard settings. I finally found a language option within the actual keyboard itself! Ah ha! Once I tapped the language option I found that you can choose from many different layouts on the actual keyboard. This is how I fixed it:
If you're using Swift keyboard, go in like you're sending a new text, from here tap the settings icon (sprocket, found on the top bar of the keyboard), then the sprocket+ icon on the right. You should see the 4 boxes that you can change for the keyboard (Languages, Themes, Typing, Account). Tap languages and then tap the language that you have set up under Your Languages. This will give you the option that you have now, but if you swipe to the left, it will show all of the different options you can choose from. Find QWERTY (or whatever you want to use) and tap on that keyboard. You will see a check mark, showing that you will now use this option.
Now go out and try the keyboard again and you will see that your keyboard is what you wanted it at..... then do a happy dance.

For Samsung phone with Samsung Keyboard:
Work On Android 14 (!!!)

Open "Settings" app
General Management (near the bottom) > Samsung Keyboard setting >
Languages and types > Upper right corner (3 dots menu ⋮) > Check for
updates
Update English (US) with refresh/update button

Possible cause:
Using Smart Switch which restores old and outdated setting to new phone

Steps with screen capture:
How to Add, Change, and Manage Language in Samsung Keyboard - TechWiser

Please note it requires manual update as Android system update, Google Play, and Galaxy Store update alone does NOT update this Samsung Keyboard (!!!).


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Phone intermittently not responding to screen touches
I have a (non-rooted) Samsung Nexus S - Android 2.3.3 phone. It has recently started becoming completely unresponsive to my screen touches, despite many attempts, cleaning the screen etc. But if I put the phone to sleep by pressing the button on the right hand side, then press the button again to wake it up - I find it always immediately works perfectly again. It may then work perfectly for a minute or two until the same happens all over again. The problem can occur regardless of what apps I am using.
I have tried using task killer, just in case it was some side effect of one of my running apps, but it made no difference.
Any suggestions what I could try next? Or could it be an unfixable hardware problem?

There are two possible reasons:
A. Something is wrong with your hardware. Unlikely since you're saying putting device to sleep and resuming fixes this problem for a while.
B. Something is wrong with your software. Most probably it is misbehaving third-party software. You can try to diagnose this as following:

Visit "Developer options" under Settings, and enable the following:
1.1 Show Touches - You'll see if your touches are registered on OS level at all.
1.2 Show CPU usage
If you see that your touches are registered, but CPU usage is high, try the following options, also under debugging:
2.1 Show all ANRs
2.2 Don't keep activities
2.3 Background process limit: No background processes
Setting "Show all ANRs" may point you to a misbehaving background process. and disabling background activities may help you understand if the problem is a background process at all. The settings above are useful only for debugging, disable them as soon as you fixed this issue, as they may interfere badly with legitimate software that needs to run in the background.
Install Android SDK on a computer, connect your phone and use "adb logcat" to see a logging trace of your phone. It may provide invaluable insight into what's going on behind the scenes there.

Sounds like some great ideas - but I can't find "show touches" anywhere in settings. In "applications" -> "development" there are three options "usb debugging", "stay awake" and "allow mock locations"... nothing else.

Looked into this, apparently availability of these settings varies depending on Android version and if the phone vendor enabled them or not... I think logcat is the only easy debugging method then. You can also install a free logcat application from the market, but hooking up phone to a computer is more convenient, especially when the phone is unresponsive.

If it were me, I'd remove apps one at a time to see if that made the problem go away.  I realize this is a huge pain.

I realise it's a little late now, but in case anyone stumbles upon this thread- this was happening with my galaxy s3. Got progressively worse. All I did was go into settings>apps>all apps> samsung keyboard and hit clear data, and it now works perfectly. Hooray


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MyTouch bricked
I have a MyTouch 4G which I had to pull battery on and then when bootup came up, it just sits and hangs at the white logo screen. How do I go about fixing this?

You may have to run an ruu if you don't have a custom recovery
You could try rebooting into bootloader and doing a factory reset there (typically, turn device off, hold volume down and power till you're in the bootloader, volume moves, power selects in that screen)

Are there any examples or tutorials on how to do this? I've never had to do this before.

It's similar to flashing a custom mod - generally you need to reboot into the bootloader. HTC's bootloaders usually look for a hardcoded filename.


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Why my phone does not need to update the password?
I changed my gmail password a day ago, but my phone does not require me to put in the new one. I can still access my gmail with the old password. Why?
Phone is rooted, sim unlocked , running android 2.3

Your phone doesn't store the password, it has some kind of session key.  I would have expected it to be invalidated when you changed the password, but apparently Google doesn't do that.  You'd have to ask them why.

Are you sure that you are not seeing locally cached data? I just tried it my self and changed my Google password. Directly afterwards the GMail app wasn't able to send or receive any mails on my Desire with 2.3 custom ROM.
Warning to everybody who want to verify this on his own: If you try this on your own remember that you can not change your password back to the original one. Google saves it and you can never use it again!

I don't know if there is any support doc for that, but you can try it out: Just go to the password changing prompt and you will be shown a warning.

And I have read in a forum that the password history is not just the last 10 passwords as it is common in corporate environments.


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GPRS/Data only starts after reset
I have Karbonn A9, Android 2.3.6.
The GPRS/Data does not switch on occasionally, but once I reboot the phone I can start it.
After deactivating GPRS/Data I have to reboot the phone get either data or GPRS to connect again. What could be causing this?

Try airplane mode, is can appear to be a faster cure than reboot.

Thanks, switching to airplane mode & comae back to normal helped.

Firmware upgrade? BTW just noticed... (Out of curiousity is it GSM in India? Or is it CDMA?)

Both CDMA and GSM phones are available. But GSM is more common.

Backup your data and factory reset your device. If problem is intact, its firmware issue. Fixing it isn't easier than flashing new ROM.
The best way to work around: Disconnect Mobile Data by renaming APN. No need to factory reset or to flash new ROM. You don't need to rename APN manually. Install Widgetsoid and use its mobile data toggle widget. In settings, make sure toggle method is APN renaming. Done!


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Screen goes blank during or after the call and does not come back
I have an Android 2.3.6 phone.
The problem is the screen goes blank and unresponsive during or after the call.
I can't make or receive any call once the screen goes blank.
In Android 2.3.6, there is no proximity control.
If I do a missed call to my number, then the screen comes back.

Related: Screen goes dark and phone goes unresponsive whenever I make/receive a call

The free app Screebl Lite will fix this problem with phone calls. However, it creates another annoying problem after installation - the screen won't shut off or standby without you physically tapping the phone's power button.
Tested on a Samsung Galaxy Proclaim, running Android 2.3.6 Gingerbread.

Yeah, just hit the power button. Your call won't terminate. It may have been meant to be intuitive, to save juice.  I use Speaker a lot, and need to hit the power button to end a call.


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How to fix - SD card works intermittently, rest of the time checks for errors
I bought a new 16GB micro SD card for my HTC Desire to replace the 4GB one it came with. I copied the contents of the old SD card to the new one and my phone loaded just fine.
Then, every few hours, the SD card would unmount saying the SD card was damaged. Turning the phone on and off a few times would result in SD card either saying "checking for errors" permanently or, occasionally, working just fine for a while.
I read a little about it and saw that perhaps I should format the card on the phone itself. So I did that (via ClockworkMod Recovery and then again in the OS itself) and recopied the files. It seemed to work for a while longer, but has now again started saying the SD card is damaged.
The SD card works fine when I put it into an adaptor and into my laptop.
Could the SD card really be damaged? Is there some other formatting I should try? Should I try making multiple partitions or something? Any ideas?
My phone runs CyanogenMod 7.2 (based on Android 2.3.7).

Please also check the Q&As mentioned in the "Linked" section at the right: http://android.stackexchange.com/questions/25278/fix-a-damaged-microsd-card plus http://android.stackexchange.com/questions/7289/micro-sd-card-physically-damaged as well as maybe http://android.stackexchange.com/questions/14918/sd-card-keeps-getting-unmounted-on-my-htc-desire plus http://android.stackexchange.com/questions/7240/how-to-fix-damaged-sd-card

I never fixed this - ended up changing my phone recently and the card works absolutely fine in the new S3.

That's quite strange, as it shouldn't be connected (I mean, what has charging to do with errors on the sdcard?). But if the problem no longer exists: Glad for you! And no way to figure out what it was, as we cannot check anymore...

Have you ever tried another SDCard at that phone? Maybe the problem was with the phone itself. Anyway, I'm voting to close as "to localized" since one cannot help anymore.

@Izzy I said chaNging not chaRging :) I don't use the Desire anymore, just my new S3 with the SD card in.

@Zuul Yes, it had a 4GB one in there and that was fine. I'm happy for this to be closed because I can't test the potential resolutions any more.

Sometimes it's really strange. I had a similar problem with my Droid 2 when switching to a 16GB card: Freeze, hang, reboot. Old card (8GB) worked fine. Updated ROM from stock 2.2.2 to CM7.2 -- now the 8GB had problems, but the 16GB was working smoothly. Which was fine with me...


text:
The calculator performs the operations in correct order after all
I was wrong. I checked several sources, including rules for javascript operand calculation rules. The misconception arises because the number beside the parantheses is not bound to the parenthetical expression, which is to be treated as a number, making the equation 3 numbers worked from left to right without any add-sub to deal with. Multiple sources to cite but here is one at bottom of post.
Rule 1: First perform any calculations inside parentheses
(2=1)=3
Rule 2: Next perform all multiplications and divisions, working from left to right.
6/2*3 = 9.
Rule 3: Lastly, perform all additions and subtractions, working from left to right.
http://www.mathgoodies.com/les.../vol7/order_operations.html

So, what is your question? "Why it's like that? What should I do?" If that's your question, try experimenting using different calculators from Play Store (there are 1000s of calc apps). Use the one that gives you the right answer that you seek.. Also, give this a read: A Calculation Conundrum

@GokulNC: after answering, saw your comment +1. This particular exiample seems to be popular !

This evaluates as I expect.

Parentheses
6 / 2 (2 + 1) = 6 / 2 (3)
Left to right multiplication and division
6 / 2 (3) = 3 (3) = 9

The original expression is equivalent to 6 / 2 * (2+1). This is not equivalent to 6 / (2 * (2+1)) = 1.


text:
Is it possible to enable "double tap to wake" on android devices which do not support it?
I am an amateur android fan with abit of shallow knowledge about android and I have always had this query about whether or not it is possible to sort of enable or integrate this feature(dd2w) into my older rooted android phone ? What does it depend on or what does it take to enable it? What is the science behind it? Btw, I'm running the regular android rom.
Ps: it would be really nice if your answer would explain things simply for me to understand. Thanks in advance :D

I assume you mean double-tap-to-wake, but please edit your question to make your actual intention clear.

On some devices yes... but it requires kernel support, meaning you need a custom kernel. There are several known methods of enabling it with a custom kernel and it depends on the screen type, SoC, and other factors, but in most cases it causes an additional 2-3% battery drain per hour to support DT2W or S2W because the digitizer needs to be powered all the time and the device wasn't designed for that.
Actually implementing it is more of a development question than an Android question though, it requires manipulation of the kernel code and building a new boot image and flashing it.

+1. I felt it was better served as an answer.

Yes, by using a custom kernal.but dt2w consumes a lot of power as the touchpad sensor remains active even when the screen is off.


text:
How can I stop the camera from switching back to the launcher?
I am trying to use my camera to record some videos. I have it set up on the tripod and then go and set up whatever I'm shooting and after 2 minutes, the camera always exits and goes back to the launcher screen. So I have to restart the camera again, and then re-do whatever settings I had (like zoom in again). Is there a way to have the camera app just stay open without automatically closing? Thanks.
Edit: I'm using a Samsung Galaxy 7 with the latest OS. And I'm referring to the built-in camera app. (If there's a better alternative, I'd be glad to hear it. I've seen reviews of several but nothing that seemed compelling enough to try.)

And which camera app? Maybe try an alternative? (Disclosure: Link goes to my site)

Wow @Izzy, that's comprehensive! It'll take me a while to read through all that.

Enjoy! My recommendations are pointed out clearly. One of them was already picked by @beeshyams in his answer – clearly my favorite (I use it myself, of course).

As an alternative to this answer from beeshyams, if you cannot afford to replace your preferred camera app than try screen pinning that app.

You can pin an app's screen to keep it in view until you unpin it.
For example, you can pin an app and hand your phone to a friend. With the screen pinned, your friend can use only that app. To use your other apps again, you can unpin the screen.

Alternatively, you can use a kiosk-mode app from Play Store to temporarily restrict usage of the device to your camera app.

Thanks to Izzy's list of  camera apps
Open Camera is an excellent ad - free (FOSS),  open source camera app which has a timer that can be set from upto 5 minute delay for both camera and video. And it has voice command activation too !
Other features quoting Izzy

Developer is Almalence, known from a set of high quality camera apps (a specialist in this area) which are also available in "free trials" and paid versions on the Playstore.

The "full program" would be A Better Camera,  which combines his Night Camera, HDR Camera and more ( you can read in reviews and tutorials on Izzy's description )

This app is available at huge discount now !
Tested it and this should solve your problem. Of course, you can try other apps on that list as well


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Can not recognize Nexus 7 2013 version with USB
I am using android version 6.0.1 kernel 3.4.0-gad29d11. I have tried a laptop with windows 8.1 and desktop with ubuntu 16.04. I have tried installing ADB software and google drivers, using different usb cables, putting the device into developer mode with usb debugging on and MTP active, a galaxy 3 phone also is not recognized on either computer. Linux does not show a new usb connection when N7 attached and windows does not show any unknown/android device in device manager. All other usb functions (e.g., OTG operations, charging, etc.) work with the N7.
What can I do?

An update: using a suggestion from a similar post [1] I tried removing all usb extenders, hub, and connecting to a different usb port. I rebooted the N7 and still no connection. I tried using a different usb cable and I observed a “developer mode enabled” notification flicker briefly. I then wiggled the connector and android device showed in my device manager!
[1] Google Nexus 7 not recognized via USB

I am curious could it possibly charge yet not do MTP if the cable is connected in the wrong position? I will test further with cables, cable positions, cable extenders, etc. and edit updates here with what I find.

Concerning Ubuntu, you may be interested in this answer, which worked for me on Debian. It basically describes a way to mount Android's MTP and let it be seen on Thunar. See if it helps.

@DeathMaskSalesman thanks for the advice, I have found some of the issue is with the port only connecting at certain plug angles and I will test first in Win but then move into Linux, your method will be useful at that time.

I have had this problem on a labtop of my mom's. Maybe there is some security feature on the mainboard, I could not try it on this labtop because it is not mine, but that might be the issue. Look out for secure boot for example. (it would be interesting to know if it is a Dell, if yes this could be an issue referring to the company or kind of bios/uefi) I have tried it on another pc, desktop this time and I did not have any trouble. So if there is no option to fix it in the bios, just use another pc, (preferably a desktop) and flash on this system if you can.

Thanks, I was able to get it to work once I held the wire in a certain position in the plug. It still seems to charge when in a different position but I am going to test it further to understand why a certain connector position allows MTP. I may try removing secure boot but I have seen a similar issue on ubuntu that does not use secure boot


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Rooting multiple devices
let's say I have about 100 old kindle fires to root (or other android devices). Of course I don't want to waste days to root them one by one, is there any way to optimize the process?
Thanks

Please view this similar question in superuser: https://superuser.com/questions/833021/is-there-a-way-to-root-multiple-android-devices-at-the-same-time  (I think this is not an expert solution as the comments on the above link says, just wait for a better solution)

Write a script to do that, then root them one by one. A huge hub will significantly help the process.

Thanks, I know for sure that a company has done this, and they need more than 400 devices... I need to set an app as launcher on those tablets, is rooting the only way? In this case I think I'll need a better solution to save me some time

Otherwise, I could have some people do it for me, but none of my coworkers are... let's say tech friendly, they have never seen a terminal, can I find a more "user friendly" way to make them root the devices?

The first step must be done manually, and one extra tap (confirm a prompt) for each device is required.

Enable USB debugging (after unlocking Developer Options) for every device
Prepare the files. A custom recovery (you should find it by yourself) and a SuperSU flashable ZIP
Prepare a script and place the downloaded SuperSU ZIP and recovery IMG in the same directory. Rename the SuperSU ZIP file to SuperSU.zip and your recovery image to recovery.img
Plug in one device and run the script. Tap "Authenticate" if it prompts for USB debugging. It will reboot several times. When the device shows the normal operating system, unplug it
Repeat step 4 until all are finished.

Script (Unix version):
#!/bin/sh
echo "install /sdcard/SuperSU.zip" > openrecoveryscript
echo "cmd reboot" >> openrecoveryscript
adb wait-for-device
adb reboot bootloader
fastboot wait-for-device
fastboot flash recovery recovery.img
fastboot boot recovery.img
adb wait-for-device
adb push SuperSU.zip /sdcard/SuperSU.zip
adb push openrecoveryscript /cache/recovery/openrecoveryscript
adb reboot recovery
# You're done!


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YouTube "Connection to server lost" on WiFi and 3G, stock 4.3
I see the issue talked about online but none of the fixes work. I haven't been able to view for over a week. Does anyone have any other ideas? It also appears that some otherer html5 based videos aren't working but I can't think how to fix that.
Attempts:

Phone off and on
Clear YouTube cache
Uninstall YouTube
Check that my WiFi settings are suitable (no proxy)

Details:

Stock Nexus 4, android 4.3
Latest YouTube app
No adblocker
No root

Are you using Adblock Plus?

no, I haven't got adblock installed

Have you tried uninstalling YouTube, and re-installing it?

Are you using a Firewall?

Yes, reinstalled it and no, no firewall...

I think I found a solution to the problem "Connection to server lost, touch to retry" on Wifi. In fact I used to encounter this problem on my Samsung Galaxy S2  device. The solution is as follows:

First make sure you have a Google account which you use to download applications from Google Play Store.
Open the YouTube application on your device.
At the top left hand corner of your screen, you would find the YouTube icon with 3 short lines to its left.
click on it (touch it) and there is a pop up menu which appears
If you have not yet signed into YouTube with the gmail account, the

You seem to be missing the end of your post.

Uninstall all of the updates to YouTube and it will fix the issue.


text:
How RAM usage effects battery drain?
I'm really confused about Android memory management.
I just read here that killing apps by swiping from recent list or using task killers won't save your battery but drain more because this cause the OS to load the apps all over again next time you launch it or startup by themselves. They also said the actually thing we should worry is CPU usage, not RAM usage.
Is that mean using too much RAM doesn't drain battery? As RAM is a hardware, holding something on it shouldn't drain battery? What if I was playing Temple Run and just press home button so the app will load faster next time I launch? Or should we just press back button until the app exit as we always do? I've also searched the internet but some said it would drain battery as it sits on RAM, some said there is no difference between RAM holds actual data or nothing. Should we let go of our app-killing habit and just feel relax?
Some precise answers would be greatly appreciated. Thanks. :)

Your RAM is one of your least power-hungry pieces of hardware...

Your temple-run example might not be the best: as games can memory-hungry they either will be OS-killed rather quickly, or pro-actively will save the important data away when send to the background. It might load a little bit faster in that case because some small part is still loaded, but the game data will probably need to load anyway. A better example would be a simple twitter client: that might fit nice and cosy in your RAM until you need it again.

I doubt that there is a direct correlation between battery consumption and RAM usage. The hardware doesn't know which RAM cells contain 'used' data and which not. So there can be no difference in battery consumption on that level.
But I think that one could say that unnecessarily killing Apps causes a few extra CPU cycles when those Apps have to be re-started and therefore "uses more battery".
And yes, you definitely should let go of your app-killing habit. In most cases, Android is capable of managing the system's resources quite well and you shouldn't bother with manually killing Apps. They definitely won't drain more battery if they just idle around and consume some RAM. Of course, if those Apps are constantly using the CPU, they will drain battery (but this is usually a sign of a bug within the App or a badly implemented App).

On the other hand, there are misbehaving apps that wake up and don't go back to sleep in a reasonable amount of time. These are the apps that can very likely be causing battery woes. You can take a a look at them using Wakelock Detector

That's why I said that Apps using constantly the CPU are usually faulty or at least badly implemented. Note that I would not recommend using apps like Wakelock Detector as this functionality is now part of Android (with 4.4 IIRC).

Think of RAM like a paper notebook. You can write data into the book (with a pencil), and you can erase those data and replace them with new data, but the book's always the same weight. The book doesn't get any heavier, whatever you write in it. The same way, with current RAM technology, the battery use of the RAM is fixed, regardless of what (if anything) is stored in it.
From Android's point of view, it doesn't matter whether you leave an app with the home button or the back button. Pressing the back button doesn't kill an app or remove it from RAM. Swiping an app out of the 'recent apps' list doesn't kill the app or remove it from RAM. The only difference it makes is changing what the app shows you next time you launch it: the screen you were on before, or the main/first screen of the app.
Imagine you have a notebook (as before), and a big bookcase with lots of reference books. You can't carry the reference books around with you, so if you need to know about a subject, you have to copy the information out of a reference book into your little notebook. When you run out of space in the notebook, you use your eraser to wipe some information you don't need again, so you can copy more information into it.
All this copying is tiresome. So once you've copied some information, you want to keep it in your notebook for as long as you think you might need it. You keep track of what information in the notebook you're using right now, and what information you use often, and what information you haven't used for a while. When you want to make space, first you erase the information you haven't used for a while. If you haven't got any of that left, then you erase some information you use often but not right now. Only if you're really desperate for space (maybe there's one big subject that takes the whole notebook) do you erase the information you're using today.
This is exactly what Android's doing with your RAM. The big bookcase with reference books is like your phone's internal storage: you can't use it directly (because the books are printed, not written with pencil), so it's expensive (it takes time and energy) to copy data into your notebook (RAM) to work on.
A task manager app is like a schoolteacher who thinks your notebook looks untidy with all those pages of notes you're not using any more. The schoolteacher comes along every so often and erases whole pages of notes. This is unnecessary, because it doesn't make the book any easier to carry around: the book weighs the same regardless. Not only that, the schoolteacher doesn't know which information you use most often - he might have a vague idea, but he doesn't know as well as you do - so sometimes when he erases information, the cost is an extra trip to the bookshelf, which you wouldn't have needed otherwise.
Thinking about it this way, it's easy to answer your question. Using more RAM doesn't use any more power directly. A task manager app can make you use more power, because you're having to copy things from internal storage to RAM that you wouldn't have had to otherwise. In the same way, a single RAM-hungry app costs you twice: first you have to write all of that app's information in the notebook, and then when you finish with it, there's a lot of information that you had to erase (to make space), which you have to copy from the bookshelf again.

Haha, I like the analogy (+1). (Although, technically, if you write something the notebook it will weight just a bit more...but I'm being too critical.) Something else to note for @MinNaingOo is that, if you're running a Task Manager, that Task Manager is also using power cycles (AKA CPU) to do what it needs to do. Hence...more battery is being used.

It might also be worth mentioning the garbage collector. Your notebook doesn't just contain information you might need again. It also contains "garbage" - information you'll definitely never need again. This is because android is lazy, and doesn't even erase the garbage until it needs more memory. When you are low on memory, it will collect up this garbage to save some space. If you are low on memory often, then it will collect garbage more often, and use more battery.

@James_pic That's what the fourth paragraph is about. I don't want to additionally bring the within-app GC into it, as that's a bigger topic only relevant to programmers.

The only difference it makes is changing what the app shows you next time you launch it - Ehh, mostly true, but not always.  "Back" tells the app, "okay, I'm done", so it can do extra cleanup immediately.  I killed my data plan one day when I accidentally hit "Home" instead of "Back" from Google Maps - it kept updating in the background.

> Swiping an app out of the 'recent apps' list doesn't kill the app or remove it from RAM.
This was changed in the latest versions of Android. See e.g.:
https://code.google.com/p/android/issues/detail?id=63618

@Izkata The app is free to handle the back button however it likes: what I'm describing is the behaviour of Android itself.

As the article explained to you, it doesn't matter how much stuff is loaded into the RAM, so that's completely okay if you don't close the applications that are idle. But if the app constantly does some activity, like syncing some data, or downloading, or even recording sound, it would drain your battery, because it uses the CPU, which sucks the energy from your battery, in that case, closing the apps would be a good thing to consider. Otherwise, if you're sure that the app will not perform constant activity in the background, then you shouldn't worry about it being stored in the RAM, it's just the same as storing your files in SDCard (I mean SDCard doesn't use battery, right?).
So just relax :) I guess temple run doesn't do any activity in the background, so don't worry to leave it in the ram.
Hope I explained to you. Cheers!

Answering the question of the title: "Can using too much RAM drain battery?"
(Not your "real" question, but possibly useful for others interested in the questions title.)
Yes, when too much RAM is used by apps or services trying to run at the same time, the system may need to kill some of them very frequently, even multiple times per second, and restart them soon as they are needed by something else.
That is using lots of CPU cycles, and thus some battery capacity.
Note that is not a normal case, like "not killing some apps manually", it's a "very broken" state - but I have seen it happen, seems to be related to many services interfering and competing for memory.

There is a big difference between iOS and Android. iOS freezes the apps, Android doesn't. The logic he explains in that article cannot be applied to Android, where some apps will drain your battery while in the background. If you care about this, use something like Greenify instead of a task killer.

What is the advantages of freezing app?

If I understand correctly an android app will only use CPU cycles when its not active if its supposed to, such as a news app thats loading new articles in the background

@MinNaingOo, A ”bad” app, cannot make a user think the iPhone battery is failing.  So stopping the user blaming apple.

@MinNaingOo Read this http://www.addictivetips.com/android/greenify-allows-ios-style-multitasking-on-android-by-hibernating-apps/

@Hallucynogenyc I've been using Greenify on all of my android devices even though I didn't know much about it's advantages. Thank you for the link :)

@IanRingrose So services of user apps are not allowed to run in background of iOS?

@MinNaingOo Read this https://stackoverflow.com/questions/11417837/running-background-services-in-ios

Since main RAM is dynamic (made of capasitors which loose info) they must be refreshed.
This refreshal takes power, and a full (or used) block, should take more power to "recharge" than once containing all 0's or somehow knows it's not being used.
However, if this is actualy noticable is for someone with more electronics know/how.
I have always noticed higher battery usage on all computers when more ram is used, regardless of CPU level, but there must be some other factors at play here.


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Will wiping data from recovery while flashing ROM on device with non-sd-slot also wipe user data?
I have a noob question. I'm planning to buy an android phone which doesn't include sdcard slot. Only internal memory. I am now using HTC Desire S which include sdcard slot. I change ROM on my phone so often. What I'm worried about is, will formatting data before flashing ROM going to remove all data in internal memory as the one I'm planning to buy rely only on internal memory. Or does HTC make some partition for something like virtual sdcard space that is stay untouched even wiping data from recovery?

This site works best when there is only one question to be answered.  I suggest moving the second part into its own question.

It depends on how the particular recovery you will choose to install handles user data.
Most recent versions of commonly used recovery images (e.g. TWRP and ClockworkMod) recognize the need to keep certain portions of internal memory on devices without removable storage. On such devices the /sdcard mount point is still present, but is pointing to /data/media partition instead. When doing a regular factory reset, this /data/media partition is left untouched. If you really wish to clear that area as well, in ClockworkMod recovery, for example, you would need to navigate to mounts and storage and use the format /data and /data/media(/sdcard) option.

Year later update: at least for version 6.0.5.1 of ClockworkMod doing a "factory reset" claims it is formatting /data, /cache, /sd-ext and /sdcard/.android_secure. However my /sdcard folder (/data/media/) is still in place with all my files.

Terminology is important in this case...
Formatting /data will wipe out your internal /sdcard/ mount.
wiping /data, on the other hand, will usually not erase your sdcard.
Usually you don't need to actually format /data/, and wiping (usually called a "Factory Reset") will suffice.
Technical explaination:
/sdcard/ lives in /data/media. When doing a factory reset, the recovery will delete everything in /data/ except for /data/media/. In fact, when factory resetting, my recovery will tell me "wiping /data, skipping /data/media". However, when formatting, you cannot be selective like that. Formatting will wipe out everything on a mount point.


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Can I expect samsung mhl adapter to work on my htc?
Mine is HTC One X and I am going to buy a mhl to hdmi adapter in our local store. Can I expect samsung or other random mhl adapters to work on my HTC One X in case Stock adapters are out of stock or too expensive?

Samsung has two types of MHL cable: an 11-pin one for their more recent phones, and a 5-pin one for their older phones. The 5-pin one is standard and will work on non-Samsung phones. The 11-pin one only works on newer Samsung phones.
Third-party manufacturers tend to also sell both kinds, so look at which phones the cable says it is for. If it says it's for Samsung Galaxy S4, or if it's Y-shaped with a second USB output, then it's an 11-pin one and won't work with your phone.
See my other answer on How does MHL work? to learn more about the difference.

Be careful - I've tried this this week and was unsuccessful. I bought a Samsung Galaxy S3/4/Note etc mhl cable thinking they were all the same and the micro USB is longer than normal. It wouldn't fit in my Nexus 7 or my HTC One X.

Thank you. I heard s3 have different mhl tevhnology unlike others. But htc adapters are pretty expensive.. :(

I would recommend not to use the one for Samsung on HTC One--I tried several times both for charging and for using MHL HDMI cable connecting to TV-- the micro USB for Samsung Galaxy S4 and S5 did not smoothly fit into HTC One though they all use micro USB and they all look the same.