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My 20 year old Liftmaster does the click/fail occasionally but I have not tried to fix it.
Could it be a relay assuming it has one? I had a car that failed to start every few months or so, after a few years of this I finally isolated it to a fuel pump relay that had oxidized contacts. I currently have a car that only has about 1V across the rear defroster - may be the same type of issue.
If it has a relay perhaps you can remove the relay cover to get a look at the contacts.
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(09-19-2022, 04:16 AM)KC Wrote: I suspect that 'quality' of a new unit might be lesser than one 20 years old... so it may be worth fixing.
Amateur question... have you unplugged it for a few minutes AFTER all the things you've done?
Yes, I did. No change.
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(09-19-2022, 01:25 AM)ShopStud Wrote: The sensors seem to be working. I have green lights at both ends; however, if the beam is interrupted, the green light flickers at one end.
I ran into this today at an inspection. The door opened but wouldn't close. The lights came on and I heard the click. Both green lights on.
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I just ordered a new control panel for a 2006 era 1/2 hp Liftmaster from Ebay for a customer; used but guaranteed to work, $60. I had "repaired" the existing circuit board by soldering jumpers across a few melted tracers a few years ago. I got it working on the third try after closer examination with a magnifying glass. I don't want to try that method again. This replacement will also get a surge protector in the outlet.
Sign at N.E. Vocational School Cabinetmaking Shop 1976, "Free knowledge given daily... Bring your own container"
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(09-19-2022, 08:36 PM)Cabinet Monkey Wrote: ShopStud
The connections to the motor are not easy to disconnect. Unfortunately, there's no detailed connectivity schematic that I can refer to, to figure out what to disconnect and how to feed power to the motor without blowing everything up. Figuring this out without a diagram, with limited access to the board (because of the manner in which it is mounted and the way the wires run in), while perched on a ladder, is not much fun
I wish I could get my hands on a wiring schematic !
First, take the unit down so you can work on it on a bench. It’s not doing you much good up there if if it’s not functioning. It’ll be a lot safer too
I suspect the motor’s wires are not soldered to the controller - which means they can easily be disconnected to test.
https://www.garagedoorsupplyco.com/Liftm...c_287.html
Thanks very much. I will take the opener down this weekend and carry out the diagnostics. Will be a lot easier to do on my kitchen table. The link to the diagrams and parts list is good, but does not provide a wiring diagram. Would have made my life a lot easier.
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(09-21-2022, 12:59 AM)ShopStud Wrote: Thanks very much. I will take the opener down this weekend and carry out the diagnostics. Will be a lot easier to do on my kitchen table. The link to the diagrams and parts list is good, but does not provide a wiring diagram. Would have made my life a lot easier.
Pretty sure you’ll never find a board schematic. It’s not a serviceable part so there’s no real need for a schematic to be out in the wild.
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Start with bright light and magnifying glass. The tracers on the board are prone to melting. You might get lucky and just need a jumper or two.
Sign at N.E. Vocational School Cabinetmaking Shop 1976, "Free knowledge given daily... Bring your own container"