I'm having a problem with my Sears Craftsman garage door opener.
For some reason, the garage door won't close anymore. (Now it's only
a garage door _opener_). Neither the switch in the garage nor the
remote keypad will close it.

The light on the opener works. If I put something in front of the
safety sensor, the opener light blinks, as expected, so I do't think
it is a problem with the safety transmitter or sensor.

There is a yellow LED on the opener that blinks 5 times, pauses, then
blinks 5 times again, repeatedly. This looks suspicious, but I don't
know what it means.

The opener is a model 139.53674SRT1. It is a 1/2 hp Craftsman opener
with belt drive and an outside keypad.

I would appreciate any help on this.

Duane