The door opens fine, when I attempt to close either by wall button or remote, door starts down, goes maybe 6inches, then reverses back up. No lights flashing. Both sensors are solid green, I even checked with a magnify glass to verify if slightly blinking or not, but solid. If I walk through the signal bottom left light goes out (reciever). I noticed on back of opener next to red reset button, that an amber light flashes 5 times then stops, then again 5 times then stops. continuously

My chain has slack that when door is open, it hangs lower then the support arm an inch or 1 1/2in. when door is closed the chain is inch or 1 1/2in below support arm...is this my problem? tighten the chain? If so, how, how much, and with door open or closed? Comments please...and thanks

I didn't find my exact model opener but found one that looked similar...page 28 model 13953920DM

I made an adjustment to the down force on the back of the opener. (far right adjuster) - Move dial clockwise one or two ticks and now I can push the button once and the door goes down..My setting was on 1 and now I moved it to 3

Hope this helps someone else...