Ok.. Just try running the garage door by pushing the button and see if it catches the latch just fine. It will probably be just fine.... What your friend was trying to tell you to do is to grab the garage door and manually open or close it to catch the latch back onto the chain. You don't want to pull on the red cord when you are doing this - just grab the bottom of the door and either open it or close it to catch the latch. You REALLY don't want to do this with all your strength - or you might break something in the garage door latch.. It's usually harder to open and close the door - so it takes some strength to open it up without the help of the motor... but you want to go slowly when it's hooking the latch back up or you might break that part. Here's what is going on.... The Red pull handle thingey has a spring loaded latch inside it... kinda like how a door knob works. That latch grabs onto the hole on a plate connected to the door opener chain - and the garage door goes up and down when the motor runs. (It holds together like how a door latch holds a door closed) When you pull the string - you just pull the latch out of the hole in the metal plate connected to the chain.. like how turning a door knob lets you open a door.... and you can manually pull the garage door go up and down without the motor moving the chain. Does this make sense...

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.

Sounds like it could be a failing circuit board. There should be a part# on the back of the machine that starts with 41A_ _ _ _ _ _ (and then 5-6 numbers after). The number may also end with a letter (i.e. A, 1D). If you post the number I can cross reference it and see if the board is still available or if it is obsolete. Oh! And I will forewarn you, if the machine has been deemed "obsolete" because it no longer meets UL code, and depending on what state you live it, if you call Chamberlain directly, you will only be meet with an iron clad wall of "Sorry. I can't help you." Stinks, but their hands are somewhat tied from that standpoint.

Two easy answers. Anytime the door reverses and the main light flashes 10 times it is a sensor problem. There is no way to bypass the sensors.