Bucket Wheel Excavator not powering up? I just finished to assemble the Bucket Wheel Excavator (42055) set, I inserted new batteries in the battery box and tried to power it up.

The LED on the battery box blinks for a millisecond almost imperceptibly, and nothing happens.

I now wonder what could be the problem, I tried with several different batteries without luck, tried to clean the metal parts, but still nothing.

How can I understand if the problem is the battery box or the motor?
As Phil B suggests you really must start by testing a motor by itself from the battery box. This will confirm whether that battery box is working or not.

My experience in Radio Control has taught me to test each "electrical" bit one at a time and in a logical sequence starting from the power source until the fault is identified.

For the future it worth testing electrical things like the motor and battery box before they get "built in" to a complex model.