Question about Sears Craftsman LiftMaster Chamberlain Garage Door Opener Wireless Keypad Model 976LM Security+

4 Answers

Liftmaster garage door intermittent power loss

Lately, my Liftmaster will lose power during opening or closing, resulting in stopping of the garage door going up or down. sometimes the power somes back right away, flickers, or won't come back for a few minutes. Upon reactivation, if I push the button it will either complete is opening/closing or it will lose power again and get interrupted. If I lightly bang on the side of the unit the power will come back on or flicker, like a wire or connection is loose. I've checked all the connections, nothing appears loose or corroded, all looks normal. Could this be the board or RPM sensor?

Posted by on

  • 2 more comments 
  • Anonymous Jan 06, 2008

    I too am having this same exact problem. I have completely removed and reconnected all connections hoping to find a loose connection but to no avail.

  • Fat Fred Jan 08, 2008

    Me too! Same issue here; the door sometimes starts to open then the
    light goes
    off & it stops. I can tap on the side of the unit and the light
    will flicker and, if I'm lucky and look sideways, tap again, the light
    may stay on. In which case, the door 'may' complete it's ride up or
    down. Not always consistent in working so have to wait awhile, tap it
    again, get a solid light then press remote and it might work.

    Contacted LiftMaster last week via email but have yet to hear from
    them. Left message for the original installer but has not returned my
    call. I, as well, thoroughly checked to see if wires were loose
    but all looked secure. Have a feeling that this is a common issue.
    Purchased my opener in September of 2002.

  • Jeremy Carson Jan 10, 2008

    Actually, I just replaced the logic board and everything works great now. I figured there are only a few electronic parts that can go bad and that was the most logical place to start. Took 5 minutes and $68.

  • Jeremy Carson Jan 10, 2008

    Actually I just replaced the logic board and it works great now! I figured there are only a few electrical parts that could go bad and the logic board was the best place to start. 5 minutes and $68 to fix.

×

Ad

4 Answers

  • Level 1:

    An expert who has achieved level 1.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

I had the same problem. Although it appeared to be the logic board, on mine it actually was the connectors between the logic board and the power supply board.
There are 2 connections on the logic board. One white connector with wires going to the main unit, and another set of connectors that plug directly into the smaller circuit board that holds the step-down transformer (120vac - 22vac). These pins were not making good connection between the boards. I simply bent the pins slightly so they would make better contact on the logic board and have not had a problem since. This must be a weak point on these door openers. Purchasing a new logic board would work too, as the connectors are newer and tighter.

Posted on Oct 23, 2008

  • sailnc May 15, 2011

    This solution is definitely worth trying! No more difficult than replacing the logic board, and it's free. I tried it on my system which had precisely the same symptoms as others described here, and so far it's working well.
    Just a note -- the connector he's talking about is NOT one of the two that you removed when taking the circuit board assembly out of the main unit. (although I cleaned those up too, just in case). Once you have the 2 circuit boards taken out and on your workbench, you'll remove 3 screws that hold the two boards together, and you'll see the interconnect (I think it was red or rust colored) that seems to be causing the issue.

    Also as another data point - my system was from 2002 as well.

  • Greeny4000
    Greeny4000 Oct 10, 2017

    I did this as well and added a little solder to add a little more width to the connections. So far it works great. Thanks for this idea. Saves a ton of money.

×

Ad
  • Level 1:

    An expert who has achieved level 1.

    New Friend:

    An expert that has 1 follower.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

Mine was also made in 2002, and had the same problem. What I did is put washers under the mounting holes of the transformer/relay board which brings the connector pins on that board up through the logic board. Then, with a soldering iron, I bridged from each soldered pad to each pin to ensure the connnection. BTW, I did this with the ccas in the plastic housing on a work bench.

Posted on Jul 05, 2013

  • Anonymous Sep 02, 2015

    I had the same intermittent power problem: I also shimmed the transformer board to make a better connection to the logic board but didn't do any soldering. I did put dielectric grease on the two cable connectors and the connector that joined both boards together during reassembly...opener works perfect now!

×

Ad

Hmmm...sounds like a common problem as that is exactly what I did. It was very simple to replace the logic board and, voila, I have a fully functioning garage door with an automatic door opener that is healthy again. And, I might add, at probably a third the price of having to replace or have a technician come in and inspect/repair/replace.Thanks for everyone's input!
Fat Fred

Posted on Jan 11, 2008

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 4,402 Answers

Try a new logic boad
http://www.chamberlain-garage-door-openers.com/circuitboardcompatibilitychart.htm

Posted on Jan 10, 2008

1 Suggested Answer

6ya6ya
  • 2 Answers

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

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

With my door closed, i push door button to open and the chain and opener continues inthe closing mode. any help?


Shop for sears craftsman liftmaste... on Google


Garage Door Opener Gear...
$31.45
Sears Parts D... Liftmaster 41C4220A Ge...
$21.75
Preferred Do... Chamberlain/l... Sprocket, Gea...
$17.95
eBay Direct Replacement f...
$20.95
Moving Up G... Liftmaster 41c4220a gea...
$31.67
North Shore... Search Results

    Liftmaster Gear And Sprocket Kit 41c4220a Chamberlain ...

    www.sears.com/search=liftmaster%20gear%20and%20sprocket%20...

    Searsmore info. + -. Chamberlain LiftMaster 41C4220A Gear & Sprocket Assembly Kit. $31.40 ... Chamberlain Sears Craftsman Liftmaster 41A2817 Gear Kit. $27.65 ...

Jan 10, 2016 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

I have a liftmaster formula 1 garage door opener. for the past year, the remote will work every time if in the garage, however, outside of the garage it only works maybe 10 percent of time and then i have...


Yes, replace the remote battery. It is losing power, thus working at short range only. Loss of range is the key indicator for a remote battery going out.

--W/D--

Jan 15, 2011 | liftmaster Chamberlain Garage Door Opener...

1 Answer

Door always opens, intermittant stopping when the door is closing. Sometimes it closes all the way, other times it stops repeatedly and you must press the close button many times to get the door to close....


Sorry to say,u should of replaced the whole control box.This is not a sensors problems,it the control box problems.U know basic electronic's and soldering?Take the control box aparts,check for these bad capacitors leakages,these capacitors alway have the top of it bulges or puff up.These capacitors not giving it max power that why it work sometimes,sometimes don't.Replaced these leakage capacitors,ur power should return yo normal.

May 03, 2010 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

My Liftmaster 1/2 HP garage door opener is not working at all. There is power at the outlet. I have 3 openers and only one is having a proble.


You need to find out where you are losing the power. I would pull the logic board and look for burnt or missing traces on the printed circuit board and also look closely around the small transformer on the board for loose connections.

Jul 30, 2009 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

Garage door not closing completely


lubricate track and drive chain or screw if it resists moving too hard it thinks it hit something and will back up

Jul 09, 2009 | liftmaster Chamberlain Garage Door Opener...

1 Answer

Door opner stops/appears to lose power


How old is your unit. I need to know this it sounds like a Circuit Board problem. but would have to know how old your unit is.

Apr 13, 2009 | liftmaster Chamberlain Garage Door Opener...

1 Answer

Flight flashing on liftmaster 2000


Apparently this problem is caused by weak batteries in the remote, I changed them and that solved the problem
Steve

Jan 09, 2009 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

Chamberlain Liftmaster Sensor Problem


I think it time to replace the logic board
http://www.chamberlain-garage-door-openers.com/circuitboardcompatibilitychart.htm

Jan 10, 2008 | Sears Craftsman LiftMaster Chamberlain...

Not finding what you are looking for?
Sears Craftsman LiftMaster Chamberlain Garage Door Opener Wireless Keypad Model 976LM Security+ Logo

8,241 people viewed this question

Ask a Question

Usually answered in minutes!

Top Sears Building Materials Experts

Glenn Mayer
Glenn Mayer

Level 2 Expert

91 Answers

Mike

Level 3 Expert

4356 Answers

Cindy Wells

Level 3 Expert

5583 Answers

Are you a Sears Building Material Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...