Kingstonite.ca

Hey. Just picked up this MS Natural Ergonomic Keyboard 4000 for free (ok. It was sitting in a box of stuff at an eWaste drop off, and I grabbed it.)

I may know why it was there now... the number four key at the top of the letters keys (the 4 on the numpad works fine) and the Control key don't seem to function.

I've just torn it apart and cleaned out some dirt, but otherwise I can't see a reason for either of these keys to not be working. (i.e. no dried up soft drink spills).

Any ideas of how to remedy this type of situation? If not, I'll just drop it off at the next eWaste I see, but it's kind of a nice keyboard, so I'd like to get it to work.

BTW, it's the left Ctrl key. the right one is fine, and I need the 4 at the top of the letters because it's in an important password, the numpad one just doesn't substitute.

So far, I haven't found any other keys that don't work. Even the Scroll Lock works!

thanks in advance for any help!

How far did you dismantle it? Modern keyboards are comprised of a bunch of keys that mash two sheets of plastic with conductive traces on them together. If the material on them has been worn there's not too much you can do. However if multiple keys are toast, depending on the circuit design and the chip used, it's possible that a contact to the actual PCB that has the brains may be messed up.

These two pages have decent pictures of the guts, perhaps they'll give you some ideas:
http://gmame.wordpress.com/2008/01/18/keyboard-hacking/
http://www.modd3d.com/articles/item/keyboard-hack

I took it right apart, and removed the rubber/silicone sheet that presses down on the plastic circuit sheet. I didn't realize it was two sheets... I'll take a look at this aspect. It's pretty easy to take apart actually, just lots of screws on the back, but the keys are all nicely held in place by the top plate, so they don't go flying when it's turned upside down.

no dice. I can't find anything that looks like it's causing those two keys to not function.