« previous next »
Pages:  [1]     Go Down

Author Topic: First IBM Model M, sometimes keys won't register  (Read 9112 times)

0 Members and 1 Guest are viewing this topic.

Offline Cyberpunk

  • Thread Starter
  • Posts: 8
First IBM Model M, sometimes keys won't register
« on: Sat, 19 January 2013, 13:49:38 »
Hi, so I'm currently typing with my Model M. Sometimes, some keys (like B, N, space bar...) won't register unless I press hard on them and after that they work fine for a while  :confused:...It sucks because the keyboard is in very good condition, I took it apart for cleaning using this site http://www.preater.com/modelm/ and nothing seemed broken. I would really love to save that bad boy!

edit: It's a model 42H1295 with the PS/2 cord soldered to the PCB inside the keyboard.
« Last Edit: Sat, 19 January 2013, 13:53:56 by Cyberpunk »
Logged

Offline Cyberpunk

  • Thread Starter
  • Posts: 8
Re: First IBM Model M, sometimes keys won't register
« Reply #1 on: Sat, 19 January 2013, 15:14:39 »
Could it be that the key(s) is stuck with some dirt or the spring is bad?
Logged

Offline tp4tissue

  • * Destiny Supporter
  • Posts: 13745
  • Location: Official Geekhack Public Defender..
  • OmniExpert of: Rice, Top-Ramen, Ergodox, n Females
Re: First IBM Model M, sometimes keys won't register
« Reply #2 on: Sat, 19 January 2013, 16:12:34 »
Clean the membrane
Logged

Offline Cyberpunk

  • Thread Starter
  • Posts: 8
Re: First IBM Model M, sometimes keys won't register
« Reply #3 on: Sat, 19 January 2013, 17:51:27 »
Quote from: tp4tissue on Sat, 19 January 2013, 16:12:34
Clean the membrane

I would have to do the bolt mod? If yes, the only DIY I found was in the archive and missed pictures, do you have one to recommend following?
Logged

Offline fohat.digs

  • * Elevated Elder
  • Posts: 6555
  • Location: 35°55'N, 83°53'W
  • weird funny old guy
Re: First IBM Model M, sometimes keys won't register
« Reply #4 on: Sat, 19 January 2013, 18:31:58 »
Sandy has the quintessential guide, but forget the chisel and get a chisel-tip insert for your Xacto knife. And a soldering iron is best for making a divot to guide your drill bit.

http://wiki.geekhack.org/index.php?title=Modifications:IBM_Model_M:Nut_and_Bolt_Mod

Logged
“No political truth is of greater intrinsic value, or is stamped with the authority of more enlightened patrons of liberty: The accumulation of all powers, legislative, executive, and judiciary, in the same hands .… may justly be pronounced the very definition of tyranny.” —James Madison, Federalist 47
“All the powers of government, legislative, executive, and judiciary, result to the legislative body. The concentrating of these in the same hands, is precisely the definition of despotic government. An ELECTIVE DESPOTISM was not the government we fought for; but one .... in which the powers of government should be so divided and balanced among several bodies of magistracy, as that no one could transcend their legal limits, without being effectually checked and restrained by the others.” — Thomas Jefferson, commentary on Federalist 48

Offline Cyberpunk

  • Thread Starter
  • Posts: 8
Re: First IBM Model M, sometimes keys won't register
« Reply #5 on: Sat, 19 January 2013, 22:04:50 »
Quote from: fohat.digs on Sat, 19 January 2013, 18:31:58
Sandy has the quintessential guide, but forget the chisel and get a chisel-tip insert for your Xacto knife. And a soldering iron is best for making a divot to guide your drill bit.

http://wiki.geekhack.org/index.php?title=Modifications:IBM_Model_M:Nut_and_Bolt_Mod

Thank you! Ordered  the parts from McMaster-Carr, will keep this thread updated!
Logged

Offline ch_123

  • * Exalted Elder
  • Posts: 5860
Re: First IBM Model M, sometimes keys won't register
« Reply #6 on: Tue, 22 January 2013, 14:53:25 »
If the membrane has a fried trace (it happens) you can fix it with one of these (or something similar)

http://www.ebay.com/itm/1x-Conductive-Silver-Writer-Conductive-Silver-ink-Pen-998-/181059135607?pt=LH_DefaultDomain_0&hash=item2a27f72877
Logged

Offline rknize

  • * Administrator
  • Posts: 1731
  • Location: Chicago
    • metaruss
Re: First IBM Model M, sometimes keys won't register
« Reply #7 on: Tue, 22 January 2013, 14:56:58 »
If I were to guess, it sounds like you have some broken rivets in that area.
Logged
Russ

Offline Cyberpunk

  • Thread Starter
  • Posts: 8
Re: First IBM Model M, sometimes keys won't register
« Reply #8 on: Tue, 29 January 2013, 17:33:41 »
Quote from: ch_123 on Tue, 22 January 2013, 14:53:25
If the membrane has a fried trace (it happens) you can fix it with one of these (or something similar)

http://www.ebay.com/itm/1x-Conductive-Silver-Writer-Conductive-Silver-ink-Pen-998-/181059135607?pt=LH_DefaultDomain_0&hash=item2a27f72877

Look at the outer trace, is it fried? On the other side all the traces are fine.

Logged

Offline rootwyrm

  • Posts: 829
  • The Hands of Steel
    • My Website!
Re: First IBM Model M, sometimes keys won't register
« Reply #9 on: Tue, 29 January 2013, 17:41:10 »
Ouch. Some discoloration is perfectly normal, but that looks pretty much hosed, there. Impossible to say without testing. Simple method is to take a multimeter, set it to continuity mode, and test at contact points. But it looks burnt to my eyes.
Logged
"I remain convinced I am the only person alive who has successfully worn out an IBM Model M mechanically."
Daily Drivers: Adesso 625 (NPKC PBT / Kailh Blue), Rosewill RK9000V2 (KC PBT / MX Brown), 1994 Model M13, Sun Type4, and the rare IBM 1394540.

Offline tp4tissue

  • * Destiny Supporter
  • Posts: 13745
  • Location: Official Geekhack Public Defender..
  • OmniExpert of: Rice, Top-Ramen, Ergodox, n Females
Re: First IBM Model M, sometimes keys won't register
« Reply #10 on: Tue, 29 January 2013, 17:42:18 »
I've had traces that "looked" like that but weren't fried, but then 'others' were. Check with multimeter.
Logged

Offline Cyberpunk

  • Thread Starter
  • Posts: 8
Re: First IBM Model M, sometimes keys won't register
« Reply #11 on: Tue, 29 January 2013, 17:47:37 »
I tried most of them with a multimeter and they were all working.
Logged

Offline rootwyrm

  • Posts: 829
  • The Hands of Steel
    • My Website!
Re: First IBM Model M, sometimes keys won't register
« Reply #12 on: Tue, 29 January 2013, 18:54:46 »
Quote from: Cyberpunk on Tue, 29 January 2013, 17:47:37
I tried most of them with a multimeter and they were all working.

Okay, so there's two tests to do with the multimeter. The first is continuity - that's the 'quick' test that tells you whether or not the line is completely broken. Unfortunately, continuity is not the last word. Next step would be to do resistance test - obviously on lowest available setting. Sometimes lines will pass continuity but fail resistance. Still a reasonably quick one but takes a bit more time. You'll want to start with a known good line to get your baseline.

Given the description of the problem though, I doubt there's any real problems with the matrix. (Which by the way, you can order new from Unicomp if needed.) Most likely the backplate or barrel plate has a deformation. Which bolt modding may or may not fix. One of these days I should look into the costs for a run of heavy duty backplates to solve these issues - we have a number of local stamping facilities. (And it has to be a stamped part due to the curve.)
Logged
"I remain convinced I am the only person alive who has successfully worn out an IBM Model M mechanically."
Daily Drivers: Adesso 625 (NPKC PBT / Kailh Blue), Rosewill RK9000V2 (KC PBT / MX Brown), 1994 Model M13, Sun Type4, and the rare IBM 1394540.

Offline Cyberpunk

  • Thread Starter
  • Posts: 8
Re: First IBM Model M, sometimes keys won't register
« Reply #13 on: Thu, 14 March 2013, 12:23:16 »
So I received all the parts I need to do the bolt mod, now I just want to be sure what holes needs to be drilled. Everywhere where there was a stud minus the bottom row?

Logged

Offline rknize

  • * Administrator
  • Posts: 1731
  • Location: Chicago
    • metaruss
Re: First IBM Model M, sometimes keys won't register
« Reply #14 on: Thu, 14 March 2013, 13:11:32 »
You need to do the bottom row as well, though the diameter may be different depending on what you plan to do with those.
Logged
Russ

Offline Cyberpunk

  • Thread Starter
  • Posts: 8
Re: First IBM Model M, sometimes keys won't register
« Reply #15 on: Fri, 15 March 2013, 19:56:08 »
All right, so I drilled every holes now I'm ready to reassemble the parts but it was disassembled for weeks/months and now I don't remember what's the order for the plastic membranes. In order from the backplate: backplate, rubber mat, ?, ?, barrel plate. Gosh I feel stupid now ;P!

Logged

Offline mich

  • Posts: 156
Re: First IBM Model M, sometimes keys won't register
« Reply #16 on: Sun, 17 March 2013, 06:18:41 »
Quote from: Cyberpunk on Fri, 15 March 2013, 19:56:08
All right, so I drilled every holes now I'm ready to reassemble the parts but it was disassembled for weeks/months and now I don't remember what's the order for the plastic membranes. In order from the backplate: backplate, rubber mat, ?, ?, barrel plate. Gosh I feel stupid now ;P!
That's absolutely obvious. Membrane traces have to touch each other through holes, so the order is:

Steel plate.
Membrane with traces on upper side.
Membrane with holes.
Membrane with traces on bottom side.
Rubber mat.
Hammers.
Barrels.
Logged
Pages:  [1]     Go Up
« previous next »