Help! Apple //c keyboard & whatnot...

Start by taking it apart and giving it a good cleaning. Its just a few screws and a little convincing, and the keyboard comes off as a unit with I think just one more screw inside (which I hope to remember to put back in one of mine next time I open it up). My personal technique for cleaning a keyboard is to hold it upside down (key faces floor) and scrub with a soft soapy brush. The idea is don't get a bunch of soapy crud in the mechanism. I give it a quick rinse, then put in the top rack of the dishwasher (angled for good drainage) and run a rinse cycle with no soap. Let it dry a day or two. Optionally a dose of canned air first to get the bulk of the water out. Blow out the rest of the unit with canned air, then clean the floppy heads with alcohol or real head cleaner if you have it. Anything in a socket, or any connector I wiggle around and reseat. For the carefull or foolish brave remove one at a time and reinsert to clean the contacts. Once everything is good and dry etc. turn it on and see whats good and what isn't. I would not spend more effort than that, they are just too cheap. Reluctant machines become organ donors for the more promising.