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

If it is stuck in the open position you will most likely find the trolley is jammed against the bolt just in front of the motor unit. You will need to loosen the chain enough to release the tension and then run the opener until the door closes. While the door is closed locate the 'up limit' on the side of the motor unit and turn this control 2 full turns in the opposite direction of the arrow printed on the cover. Tighten the chain.

Look at the LED light next to the SMART/LEARN button on rear of the motor unit. You may need to remove a light lens cover in order to see it. If the light is flashing rapidly this means you have a stuck button on one of your remote controls. Take the batteries out of each remote control. When you remove the batteries from the bad remote, the light will stop flashing. This remote needs to be replaced. If one of your neighbors remote controls is inadvertently programmed into your receiver, you door will open when their remote is activated. If this happens you will need to clear out your receiver and reprogram your remote controls. Press and hold the smart/learn button for 6 seconds or until you see the small LED light near the button turn itself off. If the above steps have been followed and the symptoms continue, there may be an electronic short in either the wall control button or the receiver logic board. In this case, remove the wall control wires from terminals 1 and 2 on the motor unit. Should the symptoms persist after the wires are removed, replace the receiver logic board. If the symptoms stop with the wall control wires removed from the motor unit, replace the wall control button, and the wires leading to the wall control button.

Liftmaster garage door won't open with remote when dark outside. We thought it was because of lighting that was installed outside / above garage door (which has windows). Have tested with LED, CFL and incandescent bulbs and no bulbs at all. Works perfectly in daylight.