Came home tonight to find one of our garage doors open (not the one for the car we were in) when we were out. The 881LM is fast flashing the red and the yellow leds. I pulled the power, waited and when power back on, the flashing started back up. Unlike the thread on the 888LM, I don't get noise of any kind. I have two of these 881LMs, but only one is messing up. Both controllers are connected to Liftmaster Professional Formula 1 openers. My side works (for now) Wiring and sensors all seem to be as they should be.