I have a mc2100 on a treadmill that stopped working.
-Initially it was not working at all I found R17 burnt so I replaced it and Q1
-Next the motor would come on very fast then shut down immediately I found U2 to be bad and replaced it.
-Next the motor comes on full speed on all speed settings and continues to run with motor sparking its running so fast. I removed the mosfet and found it to be shorted so I replaced it and tried it again only for it to go full speed again and the mosfet was shorted again. You can still switch the motor on and off even with the mosfet shorted it just goes full speed everytime.
I also tried a bench test with motor disconected and I see 108VDC when any pwm signal is supplied.
I am now looking at U5 and D13 could one of these be causing the mosfet to constantly be shorted and cause the motor to either be off or full speed?
-Initially it was not working at all I found R17 burnt so I replaced it and Q1
-Next the motor would come on very fast then shut down immediately I found U2 to be bad and replaced it.
-Next the motor comes on full speed on all speed settings and continues to run with motor sparking its running so fast. I removed the mosfet and found it to be shorted so I replaced it and tried it again only for it to go full speed again and the mosfet was shorted again. You can still switch the motor on and off even with the mosfet shorted it just goes full speed everytime.
I also tried a bench test with motor disconected and I see 108VDC when any pwm signal is supplied.
I am now looking at U5 and D13 could one of these be causing the mosfet to constantly be shorted and cause the motor to either be off or full speed?