Garage Door won't open.

craftsman garage door openers are made by chamberlain.. Give them a call on their 800 number with your craftsman model number and they will help you

Remove the cover and check the drive gear. It is a white nylon gear just in front of the motor. It will be obvious if it is bad. Tell me - if it won't open how do you know it won't close?

The opener should have an antenna wire hanging out of it. Did someone/something hang on it?

The difficulty is determining if your remote or the receiver is bad. If you have another remote that works as it should then it is the remote. If you just have the one remote there is no way to tell which is bad.

If the remote opens and closes while inside the garage but not outside , there are a few things it could be. Assuming it was working fine before..
1. weak battery in remote.
2. remote itself could be bad. (unless you have more than 1 remote acting the same)
3. Logic board in opener is going bad causing limited range.Is the wire that hangs down from the opener straightened out? That is your remote antenna.Some people have coiled or even cut it off..reducing range.
4. Less likely but this can happen- interference from another electronic device, wireless routers, cell phone, new appliances etc.. can reduce remote range. Any new electronics recently purchased?

The radio frequency has been changed so the two are not compatible.

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

The problem is in the receiver on the logic board. You will have to replace the logic board. You can get a replacement part at searspartsdirect.com. Thanks BB

There is a short wire hanging down from the back of the opening motor -- pull this down as far as you can and bend it so it is pointing toward the garage door. This wire acts like an antenae.

You need to replace your reciever