I recently assembled my GoPiGo. 1 motor runs how I would expect. The other does not work at all. I have attempted a few troubleshooting tactics. I switched the motors from the left and right side. The functioning motor works on both the left and right side, the malfunctioning one fails on both sides.
I ran basic_test_all.py. The functioning motor works as expected and the malfunctioning motor does not run at all.
This is a fantastic product and I really enjoyed the assembly. Hopefully someone can help me get that motor up and running.