I have a Chamberlain model 1345 that is 11 or 12 years old. It stopped closing with the clicker recently, but I can still open/close using the wall button. Chamberlain support said I need a new board for the receiver (around $70). I hate to spend that on an old model because something else might go bad soon and I might need to replace the whole thing anyway. But I also hate to toss out a perfectly good unit (except for the closing with the clicker issues). Why can't I buy a generic remote like the kind people use to turn on a lamp wirelessly? I would replace the wall button with the receiver for the generic remote, and then the clickers for the generic remote would "push" the wall button. Has anyone ever done this? Thanks in advance for any advice.
The simplest way to fix this problem is to purchase a "universal garage door receiver" or "universal radio control replacement" which does as the asker proposes. It is a receiver box that wires into your door pushbutton circuit and pairs to a new remote.
It is also useful for modernizing fixed-code openers for security. However, I understand that the industry safety standard is that no opener without a optical beam may be retrofit or repaired; those must be replaced completely.
Unfortunately, I don't know a lot about that model opener, but depending on the real problem, you can buy replacement remotes and receivers from other vendors. I replaced the receivers on my doors a few years back with a modern rolling code unit, and that was compatible with the remotes built into my wife's Honda Accord. But my opener was designed with the receiver as a separate component that attached to the drive via a three screw terminal interface. There are are variety of vendors and dealers that are willing to sell you components, provided you know what you are looking for. Google is your friend.
Here is someone on ebay http://www.ebay.com/itm/like/132015114169 selling the remote for $17. Now if the receiver is the problem, this doesn't help. Shop around. You may find the receiver for less. It also pays to get a spare remote.