I have a 3 year old Sears 1/2 hp chain drive opener. It has worked fine
until last night.

Last night three things happened.
1) We lost power twice for about 30 seconds each time
2) It got down to 5 degrees; about the coldest it has been for a long time.
3) The wall switch on my GDO stopped working; the light on the switch was
out, but the remote switches worked normally.

About an hour latter the light was back on, and the switches worked. This
morning they were out again, but now they are okay again.

I figured it was a loose wire unrelated to 1 or 2 above, but I don't see any
loose wires.

Any ideas?