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View Full Version : Taking apart the IBM M2 keyboard... don't do it!



vwestlife
February 21st, 2009, 08:48 PM
The IBM Model M2 "slimline" keyboard, typically equipped with PS/1 and PS/ValuePoint computers in the '90s, was not meant to be taken apart. Trust me on this one. Your first clue should be that the case has to be pried open, as it is held together by plastic snaps, not just screws. As soon as you start prying it open, springs will start pouring out... a hundred and one springs! The springs are held in a slightly compressed position between the keys and the capacitive sensor film, and have little rocker arms attached to them which must be put in a certain position to work... so basically the keyboard is humanly impossible to put back together once you take it apart. Maybe you could hot-glue each rocker arm into position, but that'd be 202 glue points -- a heck of a lot of work!

http://img240.imageshack.us/img240/3369/jun232006005bp8.jpg

The reason why I attempted to take mine apart is that it isn't working anymore... the indicator lights stay on continuously and the computer reports a keyboard error upon POST. "clickykeyboards.com" reports that the Model M2 is quite unreliable, so this is not an uncommon experience. Too bad, as I think its typing feel is actually better than the regular Model M, and it also takes up much less space on your desk.

Unknown_K
February 21st, 2009, 09:24 PM
Sounds like a Nimble brand AT keyboard I worked with a weak ago. I got 3 keyboards a while back from a lady on freecyle along with some other stuff. One was a gateway that went with a gateway computer, easy to clean. The 2nd was full of cat piss (bagged and tossed it once I smelled it). The 3rd was a Nimble AT type keyboard with pastel colored F1, F5, F9 so I took it apart to wash it. It had a membrane under the keys (keys stayed in the top half of the keyboard) and a dozen screws holding the membrane to the top section so I had to take that off. Once I got the membrane off to wash the plastics 101 pieces of bent copper pieces and 101 springs flew all over the place. I put them all into a plastic tub and washed the keyboard, and then spent half an hour (after all the parts were dry) stuffing the copper pieces and coiled springs into each and every key and then forcing the membrane back into position while keeping everything from flying apart. It all went back ok and it works 100%, won't be doing that again.

MikeS
February 22nd, 2009, 12:54 AM
I *love* my M2s! Am typing this on one.

I've had a few apart for cleaning (and successfully back together); it takes patience but it can be done. Unfortunately they're prone to problems from coffee etc. seeping between the sheets.

*Remove all the keytops*, turn it upside down, remove the two screws and release all the latches. Carefully lift off the bottom cover and the PC sheets and rubber mat etc.; try not to move or lose any of the toggles.

Check for broken traces on the PC sheets and dried liquid that's seeped between the sheets, and wipe the contact surfaces with alcohol and clean dustfree rags.

To reassemble, make sure all the little plastic toggles and springs are in the proper place and properly seated (note that some locations are empty) and *carefully* put the rubber mat, PC sheets and bottom cover back. It's very easy to dislodge the toggles at this point; if you make a mistake you probably won't know until the keys are reinstalled and you'll have to do the whole thing all over again. Be careful that the springs seat properly when you put the keytops back on, and you should be in business.

Allen
February 22nd, 2009, 09:28 AM
I'm not sure the IBM Model M2 keyboard was ever standard issue on IBM PS/ValuePoints, which I think only came with the Model M or Model A keyboards. M2 keyboards were created for the IBM PS/1, and later rubber dome versions were standard issue on the IBM Aptiva. You will also find versions of this keyboard, known as M3, for terminals (with an RJ-11 connector). Although not compatible with PCs, M3 could be a good source for parts. Instructions on how to properly disassemble and clean an IBM Model M2 keyboard are here: http://www.instructables.com/id/Clean_your_vintage_IBM_M2_clicky_keyboard.

Chuck(G)
February 22nd, 2009, 10:06 AM
I'm confused.

vwestlife says there are no screws holding the M2 together, but the instructables tutorial and others say that there are two square-drive screws that hold the shell together.

Which is it?

vwestlife
February 22nd, 2009, 11:45 AM
I'm confused.

vwestlife says there are no screws holding the M2 together, but the instructables tutorial and others say that there are two square-drive screws that hold the shell together.

Which is it?
I said "it is held together by plastic snaps, not just screws." ;)

And mine is immaculately clean inside; it just doesn't work. The Num and Scroll Lock lights stay on all the time, and the computer reports "KB/Interface error" on start-up. I noticed capacitor C3 on the keyboard's circuit board has corrosion on its terminals, so maybe that's the fault, but I'm no good at replacing tiny surface-mount components. So unless someone has an M2 with a faulty keyboard sheet but a good circuit board that I could swap parts with, this one is hitting the trash. :(

Or, if someone is up to the challenge of repairing this one, PM me... :)

Chuck(G)
February 22nd, 2009, 02:25 PM
I said "it is held together by plastic snaps, not just screws." ;)


Read it before my first cuppa and it went right over my head. :sigh:

MikeS
February 22nd, 2009, 03:17 PM
I did have one with broken traces on one of the sheets, so I should have the keyboard PC somewhere; I'll let ya know if I find it.