Pioneer CDJ-500 error code E-91

Got this CDJ-500 displaying an E-91 every time you hit eject. All three mechanism mode switches check out okay. The rest of the functions are fine, i can even load a cd in eject mode (when the display says E-91) , shut door and then reset power. If however i hit eject , the door opens , but the mechanism loading motor continues to rotate towards the eject direction despite having reached its limit point. The motors attempts to turn , thereby roughing the belt up, for 5 seconds before E-91 appears on the display, after which no functions are possible until power is reset. The operating manual lists error 91 as "MECHANICAL TIME OUT Mechanical operation did not end in allotted time (INSIDE: 5s)" I don't have a service manual and am not about to spend 15 $ on such an old model, particularly because the unit works fine otherwise and the client might not want to spend too much on repair since the unit is usable. I suspect a blown port in the syscon PD4543A. Has anyone come accross any other reason (such as a missing negative voltage)that could lead to the same symptom being portrayed ?.