Hi, for the past 20 years I've been using an IBM Enhanced keyboard and it finally quit working. I like the keyboard so I checked the cable, which was fine, and after taking the keboard apart, the small circuit board seemed fine, too. Other than cleaning the digital contacts, I didn't know what else I should look for because it still doesn't work. Any ideas? Thanks.
If this is the clicky, long-throw keyboard, you are very fortunate -- it's the greatest keyboard ever put on anything that has a keyboard. Hope you can get it fixed.
Have you tried it on another computer? Have you tried another keyboard on the same machine?
The small circuit board is the encoder (or decoder, depending on how you look at such things). It converts the keystrokes into the goes to the computer. If it's electrically defective, you'll never know just by looking at it.
What does it do? Does the computer not detect it, or are some keys not working? Do the lights flash when you turn the computer on?
If it's not detected, and you're SURE the cable is fine, then the circuit board is probably bad. You may be able to repair it, but it will take some work since you're unlikely to be able to find a schematic.
If some keys aren't working, then it's probably a failure inside the keyboard itself. This isn't serviceable, so replacement would be the best option. The good news is that IBM made millions of these keyboards and you can still get them for next to nothing even on ebay. Based on the glorified laptop keyboards I see with new computers, it might not be a bad idea to pick up a few spares for the future. Andy Cuffe
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On Sat, 10 Nov 2007 07:11:48 -0800, "William Sommerwerck" put finger to keyboard and composed:
My research on the model "M" keyboard tells me that it is nothing more than a membrane keypad with a tactile mechanism. I'm still using a cheap off-brand AT/XT 101 keyboard with *real* key switches. My newer "ergonomic" wireless MS keyboard doesn't even come close (it was a prize).
- Franc Zabkar
-- Please remove one 'i' from my address when replying by email.
The keyboard is serviceable since the key matrix is a flexible circuit board sandwiched between a sheet of steel and a piece of hard plastic that holds all the keys. Those outer pieces are held together by rods molded into the plastic that have been heated and pressed flat against the steel, creating plastic heads almost the size of dimes. Cut off those heads, and the circuit board can be removed and worn contacts repaired with a Circuit Works silver circuit board repair pen.
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