Probably a failed drive transistor T1D or T2D or something else in the speed control since it works in bypass, that pretty much tells you your contactors, cables, and motor are functional. If you don't have service information on this machine try to do a comparative analysis with the transistors and look for the odd man out. Use your nose they usually stink when they fail, if you find one that failed try to swap the pump transistor with the suspect transistor and see if the problem follows.