LiftMaster garage door opener problems

[DesignGuy]

I recently had to replace my LiftMaster 1260LM garage door opener's receiver board after an electrical surge damaged the old one. I also replaced both sensors and the wall control.

While the door goes up and down fine, the wall-mounted control does not. The control has a large button for open and closing the door which works fine. However, the light button and the lock button do not work. The light button will turn the light on but not off. The lock button actually operates the door in the same manner as the large door button (!). I have double and triple checked my wiring.

I substituted my old wall control and same thing happens. The only difference I can find is that my old receiver board was a 41A4252-6A and the new one is a 41A4252-6D. LiftMaster says the difference is merely an upgrade and that the problems lies in the wiring. However, I haev check and re-checked the wiring.

Any ideas, anyone?

[TexasFireGuy]

LiftMaster is made by Chamberlain, who also makes Craftsman openers. If I'm not mistaken, don't they all use 2 stranded bell wires to connect to the controller? I don't see how wiring could be your problem. I realize that the problem may also lie with the wiring or connection of the board but, there again, there's isn't much to installing these things. It just seems to me that the problem is with circuitry, not wiring. Someone else here may have some better advice, but I would probably pay the $40 or so service call fee to have a tech come out and verify things for you.

[DesignGuy]

Thanks, and yes, 2 conductor bell wire to the wall control. I know it's not the wiring, since the wall control has a green LED behind the main button that lights up *if* it's getting voltage and *if* the wires are in the correct polarity. So not much to go wrong there....

Since I just purchased the receiver board, I may send it back for another, under the assumption that it is defective. Then again, perhaps there was a subtle change between the "A" rev. and the "D" rev. that is causing the problem.

[Rich]

[Doordoc]

The logic board (what you call the receiver board) controls the whole opener & it should have come w/ a wall panel for that revision of the board. We always change the wall panel since sometimes the older ones are not compatible w/ a newer board revision.

The easy test is to disconnect the wall panel wiring from the opener & wall panel. Connect the wall panel to the opener w/ a short piece of wire. If you still have the problem exchange the new board & the new wall panel. If the wall panel works fine, then the problem is in the existing wiring (most likely the wire being stapled too tight somewhere or something in the attic on top of the button wire).

Doordoc

[frank roarty]

When multifunction control panels were redesigned to function with only 2 wires they employed a scheme that "encodes" different buttons with different resistance values and the opener then "decodes" which function you desire based on current detected. oxidation, overlong wires and loose connections can increase resistance while wire staples and routing via sharp angle iron can partially short current. Either will cause your button to be misinterperted or undetected.

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