Any tips for restoring an old IBM Model F AT?

[Username]

I found an IBM Model F AT at my school's surplus store for $8 (!!!). Obviously I had to take it. Well, I took it apart and cleaned it and made a terrible mistake... I removed the spacebar. After searching online, it turns out that the only way to fix this is to pretty much take apart the entire keyboard. I plan to do things like replacing the foam and such. Any good sources of foam or tips in general?

[fohat.digs]

You will be taking it apart anyway if you replace the foam.

This thread of mine is about the 122-key terminal, but the mechanics of the process are the same.

https://geekhack.org/index.php?topic=48786.msg2514883#msg2514883

BTW - while it is apart you can shuffle the keys around if you prefer.

[Username]

Thanks! I don't plan on moving the keys around as I only want to change the foam and perhaps clean the plate, barrels, and springs. Just a few questions:

Since I'm not moving the keys, which steps can I skip?
I'm not very handy, so how did you clean and sand the plate? What kind of sandpaper did you use?
Lubrication of the springs isn't necessary, right?

Once again, thanks a lot!

[fohat.digs]

Depending on how much rust there is, fine sandpaper (200-400 grit) or steel wool should do it. The tricky part is removing and replacing the stabilizer tabs. I use a small flathead screwdriver and push them out from the back, hopefully you will not damage the flanges too badly. To replace them, I put the screwdriver into the "mouth" and rock them back into place from the front with the shaft of the screwdriver parallel to the plate. I do this when the final coat of paint is dry but not "cured" (always read and follow paint directions to the letter!) so that it helps "glue" them in place.

Clamps make the "sliding force fit" much easier when you re-assemble the "sandwich" of plates.

There is no reason to lube the springs.

[funkmon]

I removed the spacebar.

My friend, I was at this point a few years ago when I got an AT. Maybe 1 year ago. I don't remember anymore. Anyway, I just paid a guy to fix it.

But you're in school, you have no money and lots of time. I hope you do restore it and live the Model F dream!

[Username]

Thanks again. I get a AT to PS/2 adapter this Friday, so I have no idea if it even works. If it doesn't then I'll also be back for help on fixing that...

[c.a.t.]

8$?? WTF!

Just dismantle every pats and clean it with warm water and soap! Don't need retrobright because they are all made of pbt plastic!!

[Username]

Yep! It was part of a computer and I asked the guy working the register if I could buy just the keyboard. I don't think he knew what it was 

Oh, and it works!

[c.a.t.]

Cool!!

[Maledicted]

Yep! It was part of a computer and I asked the guy working the register if I could buy just the keyboard. I don't think he knew what it was 

Oh, and it works!

It is a Model F, they all work, and will continue to do so ... forever, with minimal maintenance.

The F AT case is painted (and is matte without any apparent protective coat), so be ginger with it if cleaning it.

Nice find. I wish I could find a Model F for that little money, although I think I would feel guilty not offering more.

[Username]

Just an update: I replaced the foam and I'm trying to reassemble the keyboard. However, I'm unable to get the spacebar to work properly. It will go down and click just fine, but it won't return upwards. Any idea how to fix this?

[fohat.digs]

Obviously a stabilizer problem. I haven't had an AT or an XT apart in at least 3-4 years and honestly don't remember how they work with that long "undercarriage" on the underside of the plate.

[headphone_jack]

Just an update: I replaced the foam and I'm trying to reassemble the keyboard. However, I'm unable to get the spacebar to work properly. It will go down and click just fine, but it won't return upwards. Any idea how to fix this?

Could you provide a video of what you mean? Depending on the mechanics of this it could be a few problems, but most likely is the stabilizer is installed backwards or incorrectly.

[Username]

Well, I found the issue, and you were exactly right. The bar, despite looking symmetric, is not symmetric. Now everything is put back together, and works perfectly except for the enter key. It registers, but doesn't really click. I may need to keep trying to reseat it.

[headphone_jack]

Well, I found the issue, and you were exactly right. The bar, despite looking symmetric, is not symmetric. Now everything is put back together, and works perfectly except for the enter key. It registers, but doesn't really click. I may need to keep trying to reseat it.

Look closely at the spring. Is the "compressed" bit at the top wound up fully? If not, then new spring time. If it's not that, it's either an incorrectly seated keycap or the flipper is stuck in the barrel plate and you'll have to disassemble it to reseat it.

[Maledicted]

Well, I found the issue, and you were exactly right. The bar, despite looking symmetric, is not symmetric. Now everything is put back together, and works perfectly except for the enter key. It registers, but doesn't really click. I may need to keep trying to reseat it.

Most likely, yes. Pull the cap and tilt the keyboard so that the spacebar is on top of the rest of the keys and the cable is pointing down.

Verify that the coil spring is relatively centered in the barrel from side to side but drooping casually a little downward.

Pop cap back into place and test.

If reseating this exact way a few times doesn't work and the spring looks like it may be misaligned, I stick some really narrow needle nose or tweezers down there to try to make sure the spring is perfectly aligned on the nub on the flipper until things look right. (I have done this even to replace the spring entirely once or twice without disassembly) Some people have rigged up tubes of roughly the same outer diameter as the spring and pushed something like a chopstick down the center as well for the same purpose. If the spring seems kinked no matter what you do, you might need to pull it off entirely and either replace it or try to reshape it.

[fohat.digs]

tilt the keyboard so that

Some people have rigged up tubes of roughly the same outer diameter as the spring and pushed something like a chopstick down the center

Sometimes you have to tilt it in more than one direction. Also, you should be able to lightly flick the spring and have it flop around a bit. If it doesn't, the pivot plate ("foot") is probably wedged immobile somehow.

Years ago somebody came up with a way to use a slightly modified 1/4" pop rivet (including the shaft that is usually cut off after you "pop" it) that was supposed to be super easy and accurate, but I have never been able to find it again.

[Username]

Reseating the flapper worked! All good now. Thanks for all of your help!

[jacobalbertus1]

i love model f's if the board stops working i can literally replace the controller and its almost guaranteed to work also an at if this one was mine i would ansi mod it and add alt keys