Shutter stuck after triggering, no power going to shutter motor

I fully disassembled my NEX-5R to fix the lens interface and when I put it back together the shutter failed. The front curtain closes but then the motor that is supposed to wind it back does not run. I tested the motor with external power and it spins normally so the issue is that the main board is not sending any power to the motor, instead it just closes the front curtain then gives a camera error. Why is this happening?