I suspect that your drive has suffered an overvoltage on either the +5V or +12V input. This usually results in a shorted protection diode (TVS diode). The simple fix is to remove the shorted diode with flush cutters. However, be absolutely certain that your power supply is OK, as your drive will no longer have overvoltage protection on the affected supply rail.
If you can upload a photo or scan of the component side of your PCB, one of us will help you identify the faulty component.