Garage won't stay closed

[bob91343]

I have an old Sears garage door opener that lately has been getting cranky.  It will close when I push the button but immediately reopens.

I checked the sensors and they are fine.  I adjusted the closing point.  Yet it still only stays closed sometimes.  It's intermittent.

Does anyone have a diagram of these things?  Maybe it's a bad relay contact.

[floobydust]

You'd have to give us a model number.
There is also a motor current high-torque trip, it might need a lube job on the chain, rails etc.
I thought they just stop when squishing someone (high torque), whereas the light beam causes it to immediately reverse.

I would check the wiring to the sensors, some openers are two-wire with fail safe so a loose wire is the same as a blocked sensor. Some sensors misbehave at low temperatures.

Otherwise I would suspect the capacitors or power supply, as they are on 24/7.

[GreyWoolfe]

Same thing happened here.  Door would close fully and then reopen immediately.  Since the door/opener is only 4 months old, we let the company resolve it.  I wasn't home when the tech came so I didn't get accurate info but it sounded like the door close limit needed reset.  Since I wasn't there, I don't know what he did to fix it.

[DDunfield]

Is it closing *all* the way before re-opening? ie: Is the bottom of the door going right down to touch the ground?

If so, it probably is the limit switch.
Opener thinks it can put the door slightly further down than it actually can, runs into the floor and hits the excessive current detector (intended to reverse door motion if it hits something that stalls the motor on the way down).

You can usually tell this is happening by watching the connection between the chain/belt and the door as it bottoms out, the physics will change from fairly low force - due to springs, door may be pulling down a little, or up a little - to a lot of force as opener tries to ram door into the ground. On mine the metal arm visibly moves at this transition (which I how I know it is time to clear the ice in the winter)

How to fix depends on the opener. Newer ones have a setup function where you have to slowly put the door up and down and set the limit in software.

Older ones used a reduction mechanism with microswitches to detect the limits. There's usually a couple of screws in the back of the opener which move the upper and lower limit switches. Turning the lower limit switch one way will make it worse, the other will cause the door to stop higher and higher above the floor. Basically you want to find the spot where it stops with the weather seal in contact with the floor, but not pinched down hard by the door.

Dave

[DDunfield]

I checked the sensors and they are fine.  I adjusted the closing point.  Yet it still only stays closed sometimes.  It's intermittent.

If you've already tried adjusting the lower limit, then it could be that you have a failure in the limit switch.

On a newer opener this will be a device to count movement, but I would expect you would be having problems at the upper end as well if this were the case.

If the opener is old enough to have mechanical upper/lower limit switches, perhaps one of those if failing.

Given that it sometimes stays down, you should be able to confirm this:

Set the lower limit so that when it stays down, it sits a couple inches above the floor.
Then see if when it fails, it goes all the way to the floor. This would indicate that the limit switch was not seen. Could be a bad switch, connections, corrosion etc.

Dave

[envisionelec]

I had this exact issue with one of my openers and it turned out to be an intermittently broken wire at one of the sensors. The vibration of the track when the door traveled nearby was enough to interrupt current to the sensor and the motor unit reversed.

[cvanc]

I assume you are turning trimpots to make some of these adjustments, could they be going bad and not holding a stable value?

[bob91343]

After reading all the helpful comments, I will try to reset the lower limit again.  When I did it, my daughter was on the ladder turning the adjustment and perhaps she was a bit insensitive with it.

Thanks to all for the help; I will report back when I have more information.

[IanB]

My Sears garage door has a physical limit switch next to the drive shaft that can have its position adjusted on the rail. When the door reaches the end of its travel a trigger hits the switch which turns off the motor. This is always the thing I adjust first.

Another problem I have encountered is spiders' webs in front of the optical beam sensor. This confuses it and makes it think there is an obstruction in the way. I trust you have checked that?

[bob91343]

Yes the sensor setup is working perfectly.  It was the first thing I suspected.  I almost routinely wipe the lenses and make sure nothing is blocking the path.

I'm voting for the need for adjustment.  When my daughter comes home I'll do that with her.  She remembers how far she turned the setting.  I will see if we can set it to ALMOST close rather than solidly close.

[SilverSolder]

The old mechanical units seem to be surprisingly reliable.  The ones here are around 40 years old,  don't have light beam sensors or other such new fangled stuff!  The "brains" are bimetal switches that are heated up...  to turn the lights off after 5 minutes, for example, but also motor overload.  To adjust the timeout you simply bend a contact!  Job done...

[floobydust]

New garage openers are WiFi and dependent on the cloud for authentication on the cellphone app.
On the phone, you can open or close the door, or know when your cheating wife comes home for a romp.
They use tiny DC brushed motors with gearing so slow you will fall asleep waiting for the door to open. A hamster in a wheel has more power.

I keep repairing old openers because they are tougher, although I ditched an old Stanley opener because the RF remote control had no security. It was a plain serial pattern and copycat attacks would let you in.

[SilverSolder]

New garage openers are WiFi and dependent on the cloud for authentication

...and no doubt only sold on a subscription basis!  -  Subscribe to your garage, only $12 per month!

[bob91343]

We adjusted the door.  We can make it so it only closes halfway but still when it reaches end of travel, it reverses and opens.  Sensors are working properly.

Is there a diagram for this unit?

The model number is 53985 Sears.

I don't really want to buy a new one, partly for some of the reasons mentioned and partly because I think there is very little wrong with this one.  It's also expensive and a PITA.  It'd be nice to find a bad relay or something.

[floobydust]

Sears Craftsman 53985 Garage Door Opener, it's made by Liftmaster.

Do the lights flash when it reverses? That is a safety sensors (light beam) problem.
Otherwise, if the load is too great from binding or unbalanced (torsion spring), it reverses. I would manually try move the door and see if it is not jamming.
The 41C4220A gear does wear out and self-destruct, inside you would see plastic shavings if it is worn out. Replacements are cheap on fleabay.

You can adjust the high-force trip point, it might be set too light and it reverses. Increase the down force trip point by turning the trimpot.
But something has changed where it needs more force to close. Best to know why.

[rbm]

It's probably that the door is not balanced.

You need to release the door from the drive by pulling on the cord.  Manually pull the door down until it is halfway open and release it.  The door should stay in place.  In fact, the door should stay in place no matter where you position it.  If it either drops to the ground or lifts back up, the springs are either too loose or too tight respectively.  Read the door manual to understand how to rebalance the springs.

Once the door is in balance, the motor should work properly.

[IanB]

You need to release the door from the drive by pulling on the cord.

This. If you disconnect the door from the drive mechanism by pulling the latch cord you can move it by hand to ensure it moves freely and is balanced. If it jams or becomes difficult to move anywhere along its travel that would definitely be a problem.

[bob91343]

Everything seems okay other than the reversing.  In the past I have had problems with broken springs and mounting hardware; when that happened it was obvious what needed doing.  This isn't like that; the door opens and closes smoothly as one would hope and expect.  It just won't stay closed a lot of the time.  Tonight after we tried adjusting it and gave up, the door wouldn't stay closed.  I tried several times and decided to leave it open.

Later, I closed it and it stayed closed.  This is the way it's been working - reopens much of the time and doesn't reopen sometimes.

While adjusting, it got set for only partial closing and yet still reversed, so it's not an issue with trying to close too far.  I looked up parts and see I can buy a circuit board for this model for about $80 but if I install that and it still is broken, I have wasted my money.  I just want to figure out how to troubleshoot this.

I would like a service manual so at least I can see what's in it and how to get it open.  A schematic diagram would certainly help.  If I have a bad relay (I assume there are relays) then maybe I can replace it or clean it or, in the extreme, replace the assembly.

[IanB]

I haven't seen you talk about all the possible adjustments for the door (e.g. force adjustment? limit stops?), nor have you mentioned what happens if you pull the emergency release cord and move the door by hand. In case it helps, here are some pages from the installation guide of what might be a similar door.

[bob91343]

Yes I have tried all the adjustments but just to make sure I will go over it all again.  My daughter isn't feeling well so I can't have her help; I think she is sandbagging.  I will try to find time for the exercise later today.

Yes I have the installation instructions.  And the door moves easily.  It's not perfectly balanced but close enough, in my opinion.  It tends to fall one way or the other depending on its position.

I installed this myself but it's been many years.  And, like some posters here, I prefer the old style to what they are selling now.  This one is made by Chamberlain and they did offer a bit of help the last time I had a problem.  The lights sometimes don't work but that's because the sockets are junk.  For years I had no lights.  Then recently one of them started working.  Then both.  Then just one again.  Chamberlain says they don't want to help because it's not branded Chamberlain.  Sears doesn't know anything, as expected.

A new board is $80, about half of what an entire unit would cost.  But I am holding off with that purchase until I have exhausted other routes to repair.

[maginnovision]

If you buy a new one... I have a Chamberlain WD962KEV and recently the power company made some changes at the utility pole which caused my house to get bad power causing AC and Refrigerator motors to burn and power to occasionally drop to a few volts. Of course the battery backup failed at some point during this and I had the same issue. On the unit though it's very easy to reset positions. You just press buttons until the door is where you want it and done. I don't use most of the features of this I just wanted battery backup but I'd really suggest buying one with easy adjustments like this.

Oh it's also quiet and was easy as any other unit to install.

[IanB]

A new board is $80, about half of what an entire unit would cost.  But I am holding off with that purchase until I have exhausted other routes to repair.

When any electromechanical device malfunctions it is much more likely that the fault is mechanical than electrical. So I would carefully examine all wiring connections and switches in the system before replacing the circuit board. Secondly, the board itself may have a relay on it that is mechanical and could fail. Or maybe even a bad solder joint on the board that has an intermittent or high resistance connection.

[bob91343]

I have fiddled with the limit and force controls many times and now it seems to be working okay.  I will reserve judgment until it's been run over the next several days.  If it doesn't reverse, I will consider it fixed.

However, it does seem that there is nothing failed in the mechanism or the electroncs, but that adjusting may make it work reliably.  I did note which way what adjustment was moved last so that if it goes bonkers again I will turn that a bit more.

I want to thank all who put in their two cents and encouraged me to keep at it.