My Sears garage door opener, which is about 5 year old and used
infrequently, appears to be kaput. Here's what going on.

1 - Door is in good balance and can move fairly easy with one hand
through it's range when disconnected.

2 - When closing, most times the door will reverse at random points.
Sometimes when first starting to close, sometimes when a foot from the
bottom, etc.

3 - It doesn't appear to be related to the eye sensors. The sensor
glows green as it should and if I break the beam with my foot, then
the door won't even start to close.

4 - Tried setting the down and up force adjustments to maximum, with
no effect.

Any ideas? I'm thinking something is shot in the internal force
sensing circuit.