Chamberlain 3/4 belt drive opener

[T56 Impala]

So I installed two of these things about 3 years ago. This morning it worked fine. Went to church and it opened and closed. Opened it when we came home and it was open for most of the day. I was working in there and is was a beautiful day!

Anyway, I go to close it and the lights flash like something was blocking the safety eye. So I checked. Nothing. Tried again and it flashed at me. Hum, tried the remote. Nothing. Tried the wall pad. Flash, flash, flash. So now I'm frustrated. Pushed the wall button again and.... It attempted to operate BOTH doors? How is this even possible? They are on completely separate wires and outlets!

So, I tried to set the limits and force. The door goes up and down but it the limit won't set. After several tries the door will open with the controllers, but won't shut unless I hold the wall button.

Any ideas? These this were not cheap. Now they don't work. (The shop side of the garage rarely gets open. It stopped working about a year ago and I never looked at it to fix it. I think the spring is broken)

 

[GS-Louie]

If you have to hold the button to get the door down something is wrong with the safety sensors. They are either dirty, not aimed correctly, or there is a problem with the wiring. Start checking them step by step.

Lou

 

[T56 Impala]

Well, here is what I did. Real simple on door #1

Unplugged it. Unplugged the back up battery. Plugged the battery back in and plugged the unit back in. Reset the up, down and force setting per the manual. Works perfectly again. Just needed a reboot I guess.

Door #2

Applied all steps from door #1. Still opens too far and would not fully close. Reset the upper and lower limits 3 times. Same results. Confirmed that the spring (internal tube type) is faulty on the RH side. Not something I can fix, so, I'm calling out a repair service to replace it.

Still don't understand why the wall switch tried to activate both of them that one time. Very strange.