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I have 2 garage doors, each with a Coromaster Mach II door opener.

If the electricity in the house goes off, or the plugs trip for any reason, one of the Coromaster Mach II door motors loses its limit settings. This also happens if the opening or closing is interrrupted by pressing the remote while the door is opening or closing. It is then a lengthy procedure to reset the limits on the problem motor, by switching off its power when it reaches open or closed positions. This has to be repeated many times - can take 1 to 3 hours. Pressing the limit button has no effect on its limit setting. The other identical unit does not have the same problem and continues to work normally after any such interruption. Any ideas?

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SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

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Posted on Jan 02, 2017

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SOURCE: Sears Craftsman 1/2hp Garage Door Opener

Thats one of the symptoms of a lightning strike or a power surge. Without actually being there I would suggest replacing the back-board. But as with lightning strikes and power surges sometimes other electronic components could have been damaged as well.

Posted on Jul 01, 2008

Door Tech
  • 98 Answers

SOURCE: Garage door opened, won't close

If you can press and hold the wall button and the door will go down, you have a photo eye issue. Check the photo eyes at the bottom of the door.

Posted on Jan 17, 2009

  • 1 Answer

SOURCE: Craftsman Garage Door not working, motor seems fine

I have similar jerkiness problem and have gone through all the nine yards of possible causes. The motor stops at random position and at random time. Even when I unhook the door from the carriage, it still showed this symptom. It started when I had one torsion spring broken. I replaced both torsion springs and adjusted for weight balance. Make sure the two cables windup properly along the thread of the pulley; Checked the photo eye sensors; checked/test capacitor; cleaned rpm sensor; adjusted all possible force settings; make sure limit switch at sound; re-programmed my remote just to check if the logic board somehow still work on this side and it did;
One important observation I have is that when I adjusted the carriage chain, I've noticed that the opener unit turns off and on as if there's a loose connection/contact. This I pursued more. The more I investigate, I spotted a "tiny" spark on one logic board soldering at the transformer footing as I **** the back panel (where the board is mounted) back and forth to simulate the on/off due to the loose contact observed earlier. This one solves everything! All I had to do is take the logic board out and re-solder that failed connection and Hooray - it fixed the problem!
Hope this helps someone with similar issues,

Canton, Mi

Posted on Jun 18, 2009

  • 3197 Answers

SOURCE: Door will not close with remote.

The code you are seeing with 5 blinks is "RPM sensor or motor overload." We can eliminate the motor overload because the door is trying to close. The RPM sensor is a small printed circuit board just in front of the motor. It's a snap to replace and is available at any good door opener company. They will know exactly what you are talking about if you ask for an RPM sensor board.

Posted on Aug 26, 2009

  • 504 Answers

SOURCE: My genie H4000A garage door opener will not





Posted on Oct 07, 2010

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