You didn't meantion how old it is... from the details of the age of being introduced in 1985, I suspect it is well loved.
If you have the skills to open it up while it is off, and in soldering... I would suspect the switch is a through-hole switch. From the part number, you might be able to find a replacement (I use digikey website) and then solder the replacement into place.
If you do, take notes and pictures, and make a service manual to help anyone else who has it too.