Cut your losses and chunk the Craftsman garage door opener. Get a Genie and you will never post a question about openers on this forum again. A little research on this forum will show you hundreds of posts about those badly engineered and cheaply produced monsters. There are probably more questions about them than anything else on this forum. I recommend the Genie "Excelerator". Opens twice as fast, quiet, has two lights, and extremely reliable. See the Genie link below. Here is a link that might be useful: Genie Excelerator at Home Depot

My wife's remote for the garage door that she uses had gotten quite unreliable. Testing the battery showed that it was like new for voltage output. So the battery and contacts were buffed with a rough cloth ( don't use sandpaper or anything that will damage the plating) and now it works perfectly.

The problem I have is my door wont open at all. Neither the remote nor the wall button will budge it. The wall unit and the overhead opener seem to be communicating, since the lightbulbs are flashing, and turn on and off when told to. The remotes seem to have no affect at all. I replaced the chain onto the sprocket assemby and was adjusting the up and down on the main unit, Unit does nothing now when I press button on wall, is it possible to have adjusted the up/down too much to make unit not operate?Anyone have any ideas why my door won't work at all? I would expect the motor to at least chug or something, but...nuthin! Just flashing lights when i press the wall buttons. Sears Model 139.53975SRT1. HELP!

For everyone having the problem with your garage door not closing... I've read this entire blog and tried everything suggested. The force/travel adjustments would solve my problem for a while then it would come back so, if you've already checked sensors, wiring for damage/connection, adjusted the up/down force, adjusted the up/down travel here's something to try before buying a new opener: Inside the unit find the up/down travel adjustment mechanism(see photo). At the end opposite the screw-heads you turn to adjust the travel there is a gear mechanism. When these gears wear they can slip. In addition, the chassis for the gears is plastic and over time will weaken-my opener is almost 12 years old! My gears are still in pretty good shape. The problem is that the chassis would flex and allow the gears to jump hence, the reason my adjustments would work for a while then the problem would come back. Now I know this will sound like a hokey fix but I figure it is better than dropping a couple hundred bucks on a new opener...I pushed a toothpick into the hole in the main chassis where the travel mechanism is snapped in essentially eliminating the chassis from flexing and allowing the gears to slip. make sure you do this on the side opposite the gears. If you do it on the same side you will put a larger space between the gears making the problem worse. This has been working for nearly a month now. I attached a picture of the travel adjust mechanism for reference. It is difficult to see the toothpick in the photo. It is right next to the brown wire connection opposite end of the mechanism from the adjustment screw heads. One other hint: the opener will most likely get hot running the door up and down making your adjustments and will shut off (thermal overload protection). I don't know why but after this happened the green light next to the remote programming button on the back would flash 5 times-off-flash 5 times...repeatedly. I had to pull the power for a couple minutes to get the light to stop blinking. Either let the unit cool for about 10 minutes after it shuts off or to keep your unit from overheating, place a small floor fan in position to blow on the motor. Craftsman 1/2 HP model# 139.53971SRT manufacture date: 02/2000