I did buy a new craftsman 1/2 after i install everything is fin but when starting open the garage door.The garage is open and close by it self and the trolley bumps bracket.please i need help.THAN YOU

Try adjusting the "closed switch" forward a little in case the door is going too far when trying to close.

the craftman george door opener will not close the light blinks five time. what is that?

Make sure the door isn't closing too far. This will cause it to open. Your opener comes with a warranty. Call Sears repair.

With the garage door up pull the release cord to disingage the garage door it self in the up position. You can skip the disengaging step, But,It saves ware and tear on the motor.

Then using a step stool you will find limit adjusting plastic slots/screws on the side of the opener.

The left screw is for garage door down.

I would turn the left screw clockwise 1/2 turn or less. then activate the remote opener. noting which way the latching mechanism moved. and so on.

It may take a few adjustments with this proceedure to get it perfectly closed. Then activate the remote to re-engage the garage door it self.

Also, LiftMaster has a web site that you can check out.

I hate to say this but it sounds like your father did not follow the instructions when he installed the opener. Try following these instructions.

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.

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.

Try this: Loosen the chain enough that you can remove it from the sprocket above the motor. Now run the opener until the sprocket turns in the clockwise direction and stops. Reconnect the chain. This will get everything in sync and you will have to tweak the 'up and down limits' a bit to get it just right.

You apparently got a bad board. See if you can return it.

Yeh, read manual. Do both sensors have led lit. try aligning. you have safety beam problem,

Yes, it seems to be a frequency issue.  Craftsman usually guarantees 50 foot range on your remotes.  Contact Craftsman, they will probably work with you to solve the problem.