Repairing IBM Model M2

[jla]

I have an IBM Model M2 with three keys that don't register: M, N and the space bar. I can try this guide: http://www.instructables.com/id/Clean-your-vintage-IBM-M2-clicky-keyboard/.

Is there anything else I should know?

EDIT: I decided to try it again despite not doing anything to it. The three keys started working first intermittently and then it was fine.

After shutting down the computer and turning it back on, it then stopped working altogether. (Caps Lock and Scroll Lock lights on)
Now it needs soldering in new capacitors, I've read. And it almost worked...

EDIT 2: I ordered the capacitors and will attempt a repair.

[dorkvader]

What capacitors need replacing? I didn't see anything lie that in your instructables page. It sounds like you have controller issues, in which case, unicomp might be able to sell you one. ('though I wouldn't be too surprised if they don't. The M's they sell have very different controllers, just looking at the pictures.)

Do you have a DMM? Do the switches click normally? can you see if a connection is made using the DMM? (This is to tell if it's the controller or the matrix, etc.) Any pictures?

Ofcourse, please feel free to post your solution and findings.

[rootwyrm]

What capacitors need replacing? I didn't see anything lie that in your instructables page. It sounds like you have controller issues, in which case, unicomp might be able to sell you one. ('though I wouldn't be too surprised if they don't. The M's they sell have very different controllers, just looking at the pictures.)

This is correct; the M2 uses an entirely different controller from the M. I would inquire anyways, as they may have a mechanically compatible part. (I don't do much with M2's.)

Do you have a DMM? Do the switches click normally? can you see if a connection is made using the DMM? (This is to tell if it's the controller or the matrix, etc.) Any pictures?

Ofcourse, please feel free to post your solution and findings.

The M/N/Spacebar issue is not controller; it's misalignment. If it was matrix damage or controller fault, it would affect more keys and not in that pattern. Could be spring assembly or more likely the matrix sheets. I generally recommend securing the M2's matrix sheets same way they did it at the factory: scotch tape. I suspect the controller failure is coincidental.

[jla]

What capacitors need replacing? I didn't see anything lie that in your instructables page. It sounds like you have controller issues, in which case, unicomp might be able to sell you one. ('though I wouldn't be too surprised if they don't. The M's they sell have very different controllers, just looking at the pictures.)

This is correct; the M2 uses an entirely different controller from the M. I would inquire anyways, as they may have a mechanically compatible part. (I don't do much with M2's.)

I'm going off of these:
http://geekhack.org/index.php?topic=5065.0
http://www.jsyang.ca/m2kb/

It's exactly the same issue.

[dorkvader]

I'm not convinced it'a the same isssue: Lowpoly said his keyboard came up with an error (two LED's on) and would not work. Having two (cheap, old, electrolytic) capacitors fail would certainly cause it.

I guess what I'm saying is: Once you get the controller repaired, your three "intermittent" keys will probably still be intermittent.

[rootwyrm]

I'm not convinced it'a the same isssue: Lowpoly said his keyboard came up with an error (two LED's on) and would not work. Having two (cheap, old, electrolytic) capacitors fail would certainly cause it.

I guess what I'm saying is: Once you get the controller repaired, your three "intermittent" keys will probably still be intermittent.

Yup, that's what I'm saying as well, except they might not be. Repairing the controller means shifting the matrix again, which may or may not resolve it.

But yes, they're two distinct issues and the failure is purely coincidental. I agree there 100%.

[jla]

I'm not convinced it'a the same isssue: Lowpoly said his keyboard came up with an error (two LED's on) and would not work. Having two (cheap, old, electrolytic) capacitors fail would certainly cause it.

I guess what I'm saying is: Once you get the controller repaired, your three "intermittent" keys will probably still be intermittent.

I wasn't expecting that. Like I said, the keys worked for a while until it died. I'll see when I get the controller repaired. I have a multimeter.