deskthority

Hello,

Long time lurker, first time poster.

So I have a 1987 IBM Model M 1391401 that I've been using daily for over 10 years. I've always taken great care of it. It has recently developed 2 seemingly related problems on the numpad block.

The first trouble is that the minus - key often gets stuck. I checked the spring, everything seems to be in proper alignment. And the second problem which I believe is causing the first problem is that the flipper that holds the spring for the adjacent * key has somehow worked itself loose and it rattles around inside the barrel. I tried to resposition it with tweezers and then the key registers, but it ulimately gets out of alignment again causing the * key to not work and also I believe it's what causing the - key to act like it's stuck.

The keyboard has most of it's plastic rivets intact, but this issue is not only annoying but hampers the usefulness of this keyboard. Do I have to break off all the rivets and do a screw/bolt mod to fix this? I tried searching around online I've never found anyone talking about a loose flipper, could it be broken?

Photo included Thanks,

Unfortunately, I don't know if there's a way to take out the flipper itself without taking apart the whole board. That being said...

ZHENYA wrote: ↑

13 Sep 2021, 21:49

I tried to resposition it with tweezers and then the key registers, but it ulimately gets out of alignment

I'm wondering if you could realign it, then do a "Partial Screw-mod" where you can restore the tension without taking the whole board apart. I have a guide with pictures here. The Partial Screw-mod part is right at the end!

ZHENYA wrote: ↑

13 Sep 2021, 21:49

The keyboard has most of it's plastic rivets intact

For some odd reason, IBM always left out a rivet near the "-" key. Not sure if it's just my bad luck, but I never saw a rivet here, even on my mint-est of Model Ms.

This probably the reason why some of my rough Ms ran perfectly well, except for a dead - key.



I usually drill it through, and then put a screw in it.



All the sheets already have a hole ready to take a rivet here. What a mystery.

Limme know!

I had a Model F with a similar problem. This guy was the culprit:



Perhaps your M's flipper is broken in the same way?

Because mine was an F, all I had to do was tweeze open the tabs and go take a look. A Model M makes such repairs a hell of a lot more involved. Bitteneite's tip might be worth a shot. But if your flipper is snapped like mine was, then it will need replaced, and that means a full bolt mod.

Bolt mods are a lot of bother, I won't deny that! But they're not impossible or the realm of experts. Even I pulled one off! Plenty of folk swear by them as an essential long term maintenance technique for all Model Ms. I'm in no hurry to embark upon a second, however…

Muirium wrote: ↑

18 Sep 2021, 11:37

Bolt mods are a lot of bother, I won't deny that! But they're not impossible or the realm of experts. Even I pulled one off! Plenty of folk swear by them as an essential long term maintenance technique for all Model Ms. I'm in no hurry to embark upon a second, however…

I'd agree with that. If it's the flipper that's broken, a full rebuild is probably the only way.
That being said, as long as OP has the right basic tools, it should be a walk in the park!

If OP wants to do it just once and forget about it, I'd actually suggest a screw-mod. It's much easier and faster. (Especially for beginners)
And as long as OP doesn't go crazy on the screw tension, the plastic threads should hold up surprisingly well!

Bitteneite wrote: ↑

18 Sep 2021, 14:26

That being said, as long as OP has the right basic tools, it should be a walk in the park!

As someone who just finished their second bolt mod in less than two weeks...it's a very long walk in the park. Well worth it, though.

To the OP, I've had this same issue with the R key on a model M and it resolved itself upon reassembly. The flipper wasn't broken, so I assume it became crooked or misaligned somehow.