Have a Craftsman 1/2 HP Garage Door Opener, been working fine. Now when you start it you hear the motor running as normal but the chain doesnt move?

10 flashes mean sensors are obstructed... something is in the way of the door or they are not facing each other. Clear the obstruction or realign the door and it will work.

If it is not blinking when it stops, then the capacitor is blown. Replace the capacitor and it should resolve the problem.

All garage door openers have a quick release. Have you checked to make sure that is locked in place? Most have a cord hangin from it and you pull it which releases it from the chain. Make sure that is engaged and it should work.

Remove the cover from the motor unit and check the drive gear. It may be stripped.

Remove the cover and take a look. I'm sure you will find the drive gear is stripped. It is a white nylon gear just in front of the motor. You can buy one at any good door service company. The part number is 41A2817 and it comes with instructions.

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.

Try this link
http://www.garagedooropeners.us/helpgifs/chamberlain_troubleshooting.html

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

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.