Hi all,
So, I bought an IBM Model M2 keyboard cheap and it had the problem where only the caps lock and scroll lock LEDs illuminate, with none of the keys working. I picked up the recommended PS/2->USB adaptor and that didn't help. So I purchased replacement capacitors (exact same specification as original) and got a capable friend to solder them in. Curiously, he told me he tested the original capacitors and that they were showing as OK, so he doubted replacing them would actually make the keyboard work. Anyway, the keyboard does indeed work with a couple of very small exceptions... perhaps some of which you guys can give me some suggestions?
Basically all keys work except for a few on the numpad: /, *, -, 9, 6, 3 and enter. The numpad "+" key works but the computer sees it as sticking when you press it. The key doesn't physically stick, but the character keeps repeating on screen until you press something else. The only other issue I have is that the space bar feels fairly stiff and doesn't register my press perhaps 1/50 times. A couple of other keys like backspace also feel a little stiff, but not to that extent. I'm pretty sure I've replaced all the key caps exactly right, so I'm not sure if there is anything I can do to loosen them up a little?
The guy who did the soldering said that the PCB wasn't been held super tight on the right side by the retaining clips, and I could see what he meant. I maybe should've wedged something in there with the standard yellow foam material when I had the keyboard open. Could this be responsible for the few keys which aren't registering presses? Also it looks like there are some small holes on the back of the keyboard which show the yellow foam that helps keep the PCB pressed tight. Do you think I could squeeze something in there, or is another full disassembly required?
TL;DR Broken IBM M2 fixed by replacing the capacitors. Some numpad keys don't register, perhaps due to PCB not being held tight one side by the retaining clips? Stiff spacebar key.
