Question about liftmaster Chamberlain Garage Door Opener Transmitter 300MC

2 Answers

Garage door won't close

The door will open when you push the wall button but when you try to close it - it reverses, reopens and the light flashes 4 times. There is no obstruction (leaves, cob web, etc), the sensors are working and properly aligned and the door looks to be manually closing well. It is a GarageMaster 1/3 hp, which I understand is made by Chamberlain, and came with the house I bought so I don't have a manual and is probably about 12 years old. I appreciate any responses....Thanks Dee

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SAME AS ABOVE... AND IF ISNT WORKING TRY TO INCREASE THE DOWN FORCE OF THE GARAGE OPENER 1/4 TURN UNTIL CAN CLOSE IT... AND IF ISNT WORKING STILL MAYBE UR TORSION SPRING OF UR GARAGE DOOR HAS TOO MANY TURNS.. CALL A TECHNICIAN!

Posted on Mar 09, 2009

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Check if there is a shadow being cast onto one of the sensors as the door closes. We've had the rope for manually closing the door cast a shadow in full sun and trigger the "something crossed the beam" safety reverse. (Our temporary solution was to cast a shadow that remained constant from outside the door.)

Similarly check if there are any weeds or grass that are being blown or bent into the opening as the door closes. If there are plants in or near the doorway, trim them or use an herbicide to kill them and then trim the top growth after the plant dies.

Posted on Mar 03, 2009

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2 Answers

When the door closes, it automatically reopens. There are no obstructions so that isn't the issue. If I disconnect the door and cycle the automatic is closes and then immediately reopens.


make sure that the auto matic reverse circuit light is being read correctly. they is a light extending a beam of infared light, you can't see it, to a reflector across the garage at the floor level at the garage opening. There should be an indicator light, usually green and red. Line up the light and reflector until the green light comes on.

Mar 08, 2011 | liftmaster Chamberlain Garage Door Opener...

5 Answers

I have a problem with a guardian 21230L garage door opener when you push the button the light flashes but no door movement happens can you help cheers Tom


I have the same problem. Door does not open or close when press the push button and/or transmitter. The light flashes 5 times. Manually open or close the door is ok. On the manual troubleshoot, it says it's either the opener is overheated or it's on vocation mode. I don't know how to switch of vocation mode. Is it possible the thermal sensor is broken?
Can someone help?

Jan 28, 2011 | liftmaster Light Switches & Dimmers

1 Answer

Door opens OK using the remote or wall push button switch Door will not close on either remote or wall push button switch Door will close if we hold wall push button until door closes How do we...


Use the pull cord and disconnect the opener from the door.

Operate the opener and let the carrier slide back away from the door.

Is the carrier moving smoothly when disconnected?

Next, lift the door by hand from the bottom to the top. Is it moving smoothly?

If not, lubricate the axles of all the rollers on both sides of the door.

Check the cable pulleys at the top sides of the door channel, lubricate them as

well. Are all cables in all the pulleys, there are 4.

After checking those things, there is a "up force" and "down force"

adjustment on the opener, try increasing the "up force" by turning the

adjustment in the direction of MORE force.

Give me some thumbs up if this helps you.

Gary

Dec 14, 2010 | liftmaster Chamberlain Garage Door Opener...

1 Answer

My Lift Master Formula 1 is not closing all the time. It will close about 1~2 feet the reverse and reopen. This happens using the remote and the manual button. Also, after it reopens the light blinks...


I recommend this to everyone with garage door opener problems:

Use the pull cord and disconnect the opener from the door. Operate the opener and let the carrier slide back away from the door. Is the carrier moving smoothly when disconnected? Next, lift the door by hand from the bottom to the top. Is it moving smoothly? If not, lubricate the hubs of all the rollers on both sides of the door. Check the cable pulleys at the top sides of the door channel, lubricate them as well. Are all cables in all the pulleys, there are 4.

Gary

Dec 10, 2010 | liftmaster Chamberlain Garage Door Opener...

1 Answer

Garage door won't close unless I hold down the wall button until it is fully closed. Checked the L.E.D light at motor and it flashes 2 times in about 8 seconds. Sensor with amber light is on, other does...



WHEN HOLDING IT DOWN MAKES THE DOOR CLOSE PROPERLY THE PROBLEM IS IN THE SAFETY EYES.


CHECK FOR A LOOSE OR BROKEN WIRE.

ARE THE EYES WIRED CORRECTLY?

ARE THEY AIMED AT EACH HOLDING DOWN THE WALL BUTTON OVERRIDES THE SAFETY EYES.

Oct 09, 2010 | liftmaster Chamberlain Garage Door Opener...

1 Answer

Just wall switch works transmitters won't light


You probably have the opener lock turned on. Press and hold the lock button on the wall button pad for four seconds. The green light will go solid instaed of flashing

Jun 14, 2010 | liftmaster Chamberlain Garage Door Opener...

1 Answer

All of a sudden our garage door stopped working and the light flashes 10 times. Liftmaster Model 2265 1/2HP. Any ideas?


We just had the same problem this morning (cold weather can mess these things up). Not sure what you mean by "not working". Ours would open part-way and then stop (or close part-way and then stop), but could open/close all the way if we held the button on the wall down the entire time it was lifting. After much research online, we ended up checking the sensors at the bottom of the garage door tracks to make sure that the green light was solid (not flashing). Ours flashed a bit, so we cleaned the "eye" and tightened it in place. Once the green was solid, we thought we were done, but still had the problem.

Then we began adjusting the screws on the unit itself that show pictures of the door opening and closing. We thought we were adjusting the torque in the unit (because we read online that cold weather can make it more difficult for the motor to work), but in reality we were adjusting the opening and closing "distance". Apparently cold weather can also do something to the tracks, which can require adjustments to be made. Something to do with ground swelling...

Anyway, we also discovered that when we had closed the door manually (red pull-cord) the night before for lack of a better solution, it never properly locked back into position, which was adding to the problem.

So, first, try cleaning the sensors. You need a solid green light for them to function properly. Second, if you have used the manual cord, make sure the arm that it attaches to is locked back into position. You can accomplish this by pulling the manual cord, manually closing the garage, and then pushing the button on the wall. The door arm should lock into place. Third, try using a screwdriver to adjust the open/close distance. Start with a 1/4 turn for each position, and play with it until you find the right setting.

If these suggestions don't address your problem, this link worked for us...http://forum.doityourself.com/doors-windows/368278-garage-door-wont-go-down-cold-weather.html

Oct 10, 2009 | Light Switches & Dimmers

1 Answer

I have 2 liftmaster 3245. The hand held remotes were working fine then stopped. I replaced the batteries and turned of all electrical/RIF close by. Still not working. Both cars operate the doors with no...


You need to reprogram the remotes by briefly pushing the learn button on the garage door opener until it flashes once, then release the button on the garage door opener.

Now press the remote button once until you hear the garage door opener click, now press the remote button once again and the remote should be programmed to work for that garage door opener.

DO NOT press and hold the garage door opener learn button for more than 10 seconds or you'll erase all programs and have to relearn all the remotes, including your car ones.

Hope you found this very helpful and best regards.

Aug 06, 2009 | liftmaster Chamberlain Garage Door Opener...

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