garge door opener shorting out

[dtominski]

I have a craftsman 1/2 hp. garge door opener 1 year old, that has begun to short out to the chain drive and track(sparks and kicks out the breaker). I have replaced the circuit board but it is still doing it. Is the likely problem the motor itself, or the large barrel capacitor?
regards
dtominski

[HayZee518]

Check the path of the chain within the motor housing. The shaft and drive sprocket are very close to the circuit board which is mounted up inside the housing. There must be a wire touching the chain or sprocket which became abraded. That's the first thing I'd look for, then if the motor didn't work, I'd look towards the capacitor and starting switch.

[dtominski]

Things I have tried already: 1) checked for any wires touching...none.
2) swaped out the circuit board for a new one...still shorts out. 3) swaped out the motor and motor starter capacitor...still shorts out. 4) Plugged circuit analyer into outlet...lights indicate good ground, hot and neutral not reversed. 5) Checked to make sure ground wire inside unit fastened to the metal housing...it is.
Why the heck is the unit still going hot when I plug it in???!!!
Any suggestions?

[HayZee518]

could there be any plastic stand offs when you changed out the circuit board? could be shorting out from the back of the board not the component side?

[dtominski]

Plastic stand offs are there but moot. The circuit board is attached to a plastic side plate, not to a metal one. No way the cicuit board itself is touching anything metal.

[LazyPup]

Have you cleaned the chain thoroughly to insure there is no conductive debris on the chain that may be shorting it out?

Check the motor mount bolts and mounting bracket to be sure the motor is not slightly moving while under maximum torque.

[HayZee518]

good point lazypup -