We have an older Craftsman 1/2 HP opener--no manual, it came with the house. My son hit the lock button yesterday, and I tried to unlock it, but it won't work. I hold the "lock" button down until the opener light blinks takes about 10-20 seconds), then hit the remote, and nothing. I got the remote to work this morning a couple of times by doing the same thing, but as soon as I stepped out of the garage and tried the remote again, nothing (held button down, light blinked, used remote to shut the door, then hit the remote again before the door was all the way down. The door went up, I walked outside, hit the remote, nada). Same for the keypad. Do I have to completely reset everything, or is there another way to unlock this? Many thanks!