Good afternoon —
I recently came into possession of the IBM Model F keyboard that came with my Dad’s IBM AT that he purchased back in 1984, and I’m hoping to bring the keyboard back into service in some way. The inner foam has, as expected, disintegrated into a fine powder, and due to having been stored in a humid basement for something approaching 30 years, the top plate has corroded to the point where it’s no longer black, it’s actually completely white on the top instead, and the foam residue on the inside of it has left behind a rather disgusting, sticky, flaky mess that seems like it might be more trouble to clean up than to try to rescue.
I saw that you have a foam insert that, after a little trimming with some scissors, will work with an AT-layout Model F (the F107 layout, if memory serves), but when I look at the repair kits available, it seems that there are kits for every Model F except that layout. Is there a way to obtain a repair kit that has the correct foam insert for this layout?
I’m also hoping that you might be able to provide (or know how to source) a top plate for the same layout, since I’m not sure that I can strip the top plate of all of the corrosion and re-paint it without it winding up worse.
Any hints or advice would be very welcome.
Thank you!
~~ Matt Balmer
For the corrosion, you could follow recommendations for rust removal online (soaking in vinegar for a few days and then scrubbing, etc.) but other than looks even a ton of corrosion does not affect functionality.
After looking closer, what I thought was corrosion…isn’t actually corrosion, it’s mineral deposits from being exposed to hard water. I tested a small corner of the plate with rust removal solution and it just laughed at it. There is a small amount of actual rust on the plates, but nearly everything was mineral deposits.
I successfully disassembled the keyboard all the way down to the circuit board. The board itself looks largely fine, although there are a few places where some of the solder mask has had some moisture ingress (black spots over traces). Nothing serious. The solder points from the controller also had the same white deposits on them as the outside of the case, but after a little poking with a multimeter, it didn’t seem to affect any of the connections, so I’ve left that alone.
Regarding the keycaps and barrels, those got tossed in a plastic tub with hot water and dish soap and allowed to sit for a day, and then allowed to dry for a couple more. They cleaned up beautifully.
I don’t know that I can say the same for the flaps and springs. When I tried pressing keys prior to disassembly, the keyboard sounded…strange (the click sounded dull and quieter than it should’ve), and pushing keys felt oddly stiff. When I opened it up and got the spring assemblies out, nearly all of them had the same white deposits on the springs as the outside of the case. While I was able to knock a good deal of it off by simply flicking the springs with my finger, it was clear that it was interfering mechanically with the springs themselves and that was why things felt and sounded odd.
I’m in for the long haul on this keyboard as I want to get this keyboard up and running along with the machine it went with (it’s personally special to me), but I’m looking at these springs and wondering just whether they’re able to be saved or whether it just makes more sense to order a full set of replacement flap/spring assemblies.
Let me know what you think.
~~ MB