Changing code on keyless pad on old garage door opener

every so many years codes change, make sure the old keyless works with this model

Are you sure you purchased the right keypad? The model you should have is 139.53681

Yes you need a new keypad. The radio frequency of your new opener is different.

Here's the manual telling how to reset the password: http://ep.yimg.com/ca/I/aaaremotes_2150_23006614

If you know the battery is good then your keypad has failed.

If you mean wireless keypad it is like this. Locate the smart/learn button on the rear of the motor unit near where all those white wires go. Press and immediately release this and then walk over to your keypad and key in your 4 digit code and press enter.

the chamberlain company is very nice go to sears and get number of side of box... sorry I cant remember off top of my head...

GOTO
http://www.garagedooropenerguide.com/installationmanuals.html

FREE DOWNLOAD OF OWNERSMANUAL

Other sites say that the remote has become defective. Here's a link for a $15.75 replacement.

http://www.liftmasterremotesonline.com/AF-04-S390-9710.html

THE FREQUENCY OF THE UNITS ARE PROBABLY NOT COMPATABLE THEY CHANGED ABOUT 2 YEARS AGO.

SORRY - I THINK YOU NEED A NEW KEYPAD TO GO WITH THE NEW OPENER.