I took my printer to a show and tell the other day. 1 half hour drive. over large hills and more than on speed bump. I put my duel head buko in the back seat of my SUV. So every thing worked fine except my bed would not move..
First I checked all my wiring, but it looked fine.
Turns out motor control chip for bed was fried. My theory is that the bed sliding around over the speed bumps and hills made the bed motor act as a generator and fried the motor controller. Fix was easy. I am only using one print head right now. Swapped out the second print head motor control chip for the bed chip. and ordered a new chip. Live and learn.