Customized Ultimaker 1: Extruder motor does not move I recently upgraded my Ultimaker 1. The upgrade includes a different stepper motor for the Extruder, the same a Ultimaker 2+ would use. I plugged the new motor and nothing happened.

To eliminate the problem I ordered a new PCB and stepper motor drivers, reassembled all electronics. For some reason the extruder does not move, and actually any other motor I plug into the extruder port doesn't either. I switched the driver, twice, but without a different result.

Can anybody tell me what component could be faulty or how I can find the problem? Could it be the Arduino board, even when I use the Ulticontroller? Maybe remove one of the jumpers next to the driver?
Did you heat the hotend before attempting to move the extruder?  Most firmwares block cold extrusion.  If you send the printer M302 it will allow the extruder motor to move without the hotend being above the temperature set in the firmware.  Jumpers next to drivers are used to set microstepping, no need to adjust these unless you changed to a different type of driver or want to use different microstepping.  Changing them usually requires changing the steps in firmware as well.  Also, swapping drivers or motors while the driver is powered can destroy it.