eq3-2 controller

[guodong]

Changed all the transistors and finally repaired:thumbsup:

[bojan]

This looks like one of the motor coils or cable for motor are at fault ( I am assuming the motor is stepper).

[guodong]

Thanks, bojan

It's a stepper motor. The motor coils looks ok. The way I burnt was: I turn on the power to controller before plugging in the cable to motor. Do you have any suggestion? Probably have to change the transistors. Still trying to solve it today :sadeyes:

Cheers
Gordon

[bojan]

Yes, you should try to change the transistors, however they are supposed to be protected from voltage spikes like that generated by plugging/unplugging cables by diodes (next to transistors)... Is anything on the board too hot? (careful, you may burn your fingertips!)
How about cable?