I got my Garage door problem fixed so thought I'd post my solution in case others have this problem. My original post has dropped off the server I think. (I just replaced the Saftey IR eyes if you don't want to read the whole thing.) Thanks to those who responded to my original post.
Problem:
------------------------------------------------------------------ My garage door opener will open but not close. It will only close if you hold your finger on the wall button the entire time. Otherwise it goes 2 inches down, then stops, backs up, and flashes the light bulbs on and off.
The infrared electronic "eyes" installed at the base of the door can see each other ok, no obstructions, and both green led's are on.
The flashing error code LED on the unit itself will flash once.
I have oiled all hinges with WD-40 as the manual suggests.
I have tried increasing the downward force with the knob located on the unit but same result even it I max it out. I've also tried adjusting the downward limiter.
The door is aluminum, two car garage type.
This opener was new in August of 1995 and worked fine for 9 years, then suddenly this cropped up.
I've seen other responses to this issue posted saying the door sensors are the culprit, but in my case both sensor lights are green. They stay green even if you put your foot in front, (should the color change if obstructed?)
Here is the specs on it:
Sears/Craftsman 1/2 HP Volts: 120 Amp: 5.0 Hz: 60 Model: 139.536415RT Chain Drive
------------------------------------------------------------- Solution:
In case anyone else has this problem, it turned out to be the safety IR eyes that were bad.
When I put my foot in front of the old eyes, the LED would stay green on both sensors. I ordered a replacement set and now the door works fine. One LED will turn off when obstructed now, so I guess that's how it should behave.
Still this will be that last Sears GDO I'll buy. I don't think something like that should fail. It has no moving parts (in the sensor) and very low power running through it. Not to mention that the replacement was overpriced - $38 (shipped) for not much more that pieces of plastic with very simple circuit boards inside. I also read elsewhere on the web that this is a known issue with Sears/Craftsman GDO's. That the eyes just stop working sometimes.