Garage door opener: motor runs but chain doesnt move.

look for a shear pin on the sprocket. you may have sheared it off or it may have never been put in.

Loosen the chain enough so that you can remove it from the sprocket above the motor unit. With the door closed run the motor until the sprocket turns clockwise and stops. With everything attached replace and tighten the chain. Some adjusting of the up and down limits will probably be required.

The chain normally comes off when there is a problem with the sprocket and gear assembly. The bearing goes bad and lets the shaft lean towards the door and the chain comes off. If this happens again you will need to replace that assembly which is part #41C4220A and is available at any good door service company.

Loosen the chain enough so that you can remove the chain from the sprocket above the motor. Run the motor until the sprocket turns in the clockwise direction and stops. With the door in the closed position replace and tighten the spring. This will get everything in sync and you will most likely need to tweak the 'up and down limit' controls to get it just right.

It sounds like your chain is out of sync with the limit switches. Loosen the chain enough so that you can remove it from the sprocket on top of the motor unit. Now run the opener until the sprocket runs counterclockwise and stops. Now with everything attached and the door in the open position replace and tighten the chain. You are now in sync. You may need to tweak the up and down limit controls which are on the side of the motor unit.

Sounds like the drive gear is stripped. Remove the cover and take a look. It is white nylon and is just in front of the motor.

Loosen the chain enough that you can remove it from the sprocket. Run the opener until the sprocket turns counterclockwise and stops. With the door in the open position replace the chain. You will probably need to adjust your open and close limits per your owners manual.

If the motor is working but the chain does not move you must remove the cover on the motor and check to see that the chain is on the sprocket. If the chain is on the sprocket and the sprocket is not moving but the motor shaft is moving then the sprocket must be retightened onto the motor shaft.

If the chain is not moving and the motor is – you need a gear kit.

Unplug the unit - take of the cover – you will find white shavings inside – these confirm the diagnosis. .

Get the gear AND sprocket kit.

It’s a good DIY project but you MUST VERY CAREFULLY Follow the instructions step by step.

HOPE THIS HELPS

2 flashes is a safety eye issue, but you problen is most likely that the chain is not sync with the limit setting. Take the bottom off the gear and sprocket assemble and rotate center limit srew until it is in the same position as the trolley.

how old is unit. sounds like gears are shot, takes $25 of parts and 2-3 hours to fix if you are handy. Take cover off, If it has white powder (Not ****), gears are shot.