Hi,
I've recently uncovered my HP-25 from the attic, where it's been since undergrad days. Rebuilt the battery pack, and everything seems to be perfect, except for a couple of keys. The "4" and "2" key have the same tactile feel as the other keys, but I have to REALLY PRESS HARD ;) on the keys for them to close the circuit. I took the calculator apart and cleaned the exposed circuit board with contact cleaner, but it didn't help. I'm afraid to try and separate the circuit board from the keyboard - it looks like they're molded together.
Any suggestions?
Thanks,
-stan