liftmaster 8550

[ralphr]

i have the above opener. about 10 years old. sensors near floor are fine one is amber one is green , neither are blinking. I have been getting an 4-2 excessive force error , and a 1-5 error. it is currently the up button flashes once and the down button flashes 5 times. I i press the down button (on the opener) it goes about 4 inches and reverses right to the stop nut. the up button doesnt do anything. there appears to be alot of tension on the belt near the motor. when i disengage the door from the opener, i can open and close it like normal. springs dont appear to be broke, door is in the track, no obstructions. any ideas?? travel module?

[TinyTool]

Hi, Ralphr! Welcome to the forum!

It sounds like your opener is struggling to figure out where it should be stopping, and that belt tension near the motor is a bit concerning. First thing I'd do is check if the belt is too tight, there should be just a little bit of slack when you press on it (maybe about 1/4 inch). If it’s too tight, loosen it slightly and see if that helps.

Since it’s reversing after moving just a few inches, the travel limits might be off. Try resetting them:

• Hold the black adjustment button until the UP button flashes, then press UP to set the open position.
• Press the black button again and do the same for the DOWN position.
• Once that’s done, reset the force settings by holding the button for about 6 seconds until both UP and DOWN lights flash.

The 1-5 error points to the RPM sensor, which tells the motor how fast it’s spinning. If that sensor is dirty, loose, or failing, the opener might not know what’s going on. It’s usually near the motor shaft, just check if it’s seated properly and not covered in dust.

If all else fails, unplug the unit for 5 minutes to see if a reset helps. But if the UP button still does nothing, you might be dealing with a bad logic board, especially considering it’s been running for 10 years. Hope one of these fixes gets it back on track! Let me know what happens.

[ralphr]

thx for quick reply. will unplugging for 5 minutes reset it if it has a functioning battery (backup)?

[ralphr]

UPDATE:

I removed the travel module. the plastic gear/teeth that come from the motor and got into sensor were broke into 4 pieces. sounds like i would need a new motor. probably just get a new unit. Let me know what you think

[TinyTool]

Thanks for the update! If the plastic gear inside the travel module broke apart, that would explain why the opener is struggling. While you might be able to replace just the motor, at 10 years old, it’s worth weighing the cost of a new unit versus patching this one up. Newer models come with improved features and better battery backups, so it might be the right time to upgrade.

That said, if you want to stretch the life of this one a bit longer, you could look into replacing just the motor assembly, but that depends on availability and cost. Either way, good catch on diagnosing the issue! Let me know what you decide to do.

[ralphr]

I learned that the 8550 has a lifetime warranty on the motor. I reached out to Liftmaster and they are sending me a new motor(with travel module) free of charge. Hopefully this will take care of my problem.

[TinyTool]

That’s great news! A free replacement motor with a travel module should definitely take care of the issue. Let us know how it goes after the swap. Hopefully, it’s just a straightforward fix!