I have a Genie PC700ML garage door opener (about 7 years old). Recently, it has been giving intermittent problems with both opening and closing. It will work for several days in a row, then in the morning, it will not be able to open up (either from the wall button or either of the remotes). I think I've been able to get it down to these symptoms.

1. Door will not open from wall or remote, no lights on either sensor. Power appears to be dead to the garage. No light on the opener. Other lights in the garage do work off the same line. Have connected by extension cord to other outlet in the garage, and one on a separate line in the kitchen. After turning the circuit breaker in the fuse box or plugging and replugging the line, the sensors go on and I'm able to open up the door. If I try to open and close, it will work a few times, then the red sensor goes to 3 flashes.

2. Door when opening or closing just stops in the middle, again as if the power is being shut off. Sensors are lined up so that red light / green light is on. Happens on both sunny and cloudy days. Cleaned sensor lenses and any debris that might cause this. Door just appears to stop at different positions on the way up or down.

Thanks for your help.