Chamberlain Belt Drive, pretty new, judging from condition/appearance (we just moved in and it was already here). The sucker won't close. The lights blink out trouble codes - said sensors misaligned. Used levels and lasers and still nothing. Replaced the sensors but no go. Now the code says either wires reversed or broken wire. Triple checked the wires, I've got voltage to all wires, the only thing is the led's on the sensors themselves aren't lighting up like they should. Should be blinking if misaligned, solid if aligned - but only one sporadically blinks, and nothing out of the other one. Anybody ever mess with one of these? I can't think of what else to try.