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geekhack Community => Keyboards => Topic started by: Oqsy on Sat, 14 November 2009, 21:56:14
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Hello all, this is my first post here, although I've been reading threads here for a while and finally dyed my Model M's keys red and back last night. However, at some point in the reassembly something went awry, and now my LEDs flash a single time (all three simultaneously) at bootup, and when I get into windows all LEDs shut off, and the keyboard appears dead after that, no LED response to the caps, num, or scroll lock keys, and no keys work. I thought it might be a shorted wire in the cable where it enters the keyboard (pretty crimped and bent up, and the insulation was split at one place. I cut and repaired all wires and rerouted the cable. Still the same response when I bootup. Any resources out there that can tell me what's wrong with the keyboard (any Model M troubleshooting FAQs etc)? By the way, great forum and glad to see there are other people that geek out over clicky keys, Model Ms and the like. Oh and I'll add some pics here later tonight of my dye results (I'm quite pleased!)
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Welcome.
Do all the keys feel normal (click when you press)? If not, maybe some keys are stuck in the 'down' state, and that is causing the board to fail its self-test.
Is it an M2? They are known to sometimes have failed capacitors. The original M doesn't (at least not as often.)
Are you connecting straight to a PS/2 port or through a PS/2-USB adapter?
If PS/2, did you plug it in while the PC was off?
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it's a 42H1292 made in Scotland in 1999. It's a PS/2 board, no USB involvement, and yes I connected it when powered off. I checked all the keys and they all click and rebound normally. I know very little about the electronics of a buckling spring, but is it possible dust/etc fell down into the mechanism and caused a short on the board, simulating a "stuck key"? just wondering if it would be worth it to take off the caps and stems and blow some compressed air inside each switch.
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Here are a couple of pics... the case is going to be NES case gray, continuing in the nintendo color theme of the board. For those looking to dye this particular type of cap, HEAT is the key. I soaked them in very strong dye at 150F (feared melting them at 170F as has been posted other places, especially the spacebar)... but nothing happened worth noting until i got to 200F or above. once the water really started churning with bubbles, I could smell the dye very strongly and the keys would take the color in a matter of seconds. Black took me about 10 dips being very careful and methodical so that I didn't ruin anything, but the red was a piece of cake. I even did the space bar by itself at the end to make sure it wasn't deforming in the heat, but it stayed solid all the way to boil, and only took about 2 minutes of up and down heat from 190-212 (on and off the burner) with rolling boil lasting no more than 15 seconds each time. These caps may be know to be particularly tough when boiling, but I wanted to share for anyone else out there that is afraid of melting their caps like I was.
(http://i400.photobucket.com/albums/pp81/Oqsy/model_m_bc.jpg)
(http://i400.photobucket.com/albums/pp81/Oqsy/model_m_dyed1.jpg)
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I think it's unlikely to be dust etc. I'm worried a short might have damaged something. Do you have other equipment to help isolate the problem, e.g. another PS/2 keyboard to make sure the computer port is OK, or another PC to try the model M on?
There have been cases where some computers haven't been able to supply enough power to the PS/2 port for 'legacy' kit of this age.
I have no personal experience of faulty model Ms. Maybe someone else has some ideas or a link.
Edit> Just saw the pic, the keys look stunning.
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yes, I'm using my logitech keyboard on this comp now, also a PS/2, and the model M was working perfectly before reassembly. I was dead set on it being the split cable insulation, but now I'm a bit worried that all my work was in vain.
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Did any of the dye get onto the controller board? (The PCB that the Leds are mounted onto)
Fortunately, you can get a new 42H1292 quite cheaply and just put your new caps into it.
Link (http://cgi.ebay.com/MINT-1996-IBM-Model-M-clicky-Keyboard-42H1292-Unit-335_W0QQitemZ130339353975QQcmdZViewItemQQptZPCA_Mice_Trackballs?hash=item1e58d4b577#ht_771wt_941)
Nice mod btw.
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Thanks for all the responses! I'll try everything suggested. The keys were bone dry when I put them on the board (hairdryer ftw). The controller board was nowhere near the dying process or wet keys so it should be fine. I'll report back once I've tested and disassembled the board.
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Ok, so I disassembled the board, stems and all, and the board DID boot normally into windows (numlock was illuminated at login screen). I started replacing stems and noticed it was taking the input from the keys (right numpad) until I got to 789... nothing. Then I started on letters... nothing on the top row (qwerty), but some letters on lower rows worked. I believe that the ribbon may have come loose or that the membrane has too much space between it and the switches, but I can't find a way to separate the black plastic tray from the rest of the board without cutting all the plastic rivets, and so I can't access the ribbon to disconnect and reconnect it, or to even check that there is no mechanical damage somewhere along the circuits. Any tips for further dis-assembly, or is a new 42H1292 the only real option at this point? I'd love the satisfaction of reviving this board, but I also know that at some point it's just not worth it anymore. Thanks to all for their comments and advice thus far!
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i mean if you are willing to buy a new one you mind as well try anything you can to fix the old one, not let some rivets stop you from even attempting to fix one that does not work
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Please double check the membrane connection at the controller board. Maybe that has partly come out.
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In a 42H1292, the controller board basically slots into the membrane (it's hard to explain, you'd have to see it for yourself) Make sure the controller is properly inserted. You may even want to take the board out and reinsert it.
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Ok, so I disassembled the board, stems and all, and the board DID boot normally into windows (numlock was illuminated at login screen). I started replacing stems and noticed it was taking the input from the keys (right numpad) until I got to 789... nothing. Then I started on letters... nothing on the top row (qwerty), but some letters on lower rows worked. I believe that the ribbon may have come loose or that the membrane has too much space between it and the switches, but I can't find a way to separate the black plastic tray from the rest of the board without cutting all the plastic rivets, and so I can't access the ribbon to disconnect and reconnect it, or to even check that there is no mechanical damage somewhere along the circuits. Any tips for further dis-assembly, or is a new 42H1292 the only real option at this point? I'd love the satisfaction of reviving this board, but I also know that at some point it's just not worth it anymore. Thanks to all for their comments and advice thus far!
I have had similar problems with my Model M after re-assembling it. If I were you, I would take it apart again and look for where the keyboard connects to the mainboard with a ribbon cable. Chances are that the ribbon cable is not plugged in properly. Gently remove it and carefully re-insert it correctly, and all the keys should work. Good luck!
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Is there a way to do this without separating the black tray and cutting all the rivets? I can see the ribbon like connector at the bottom, but the angle prevents me from accessing it without bending/breaking the main board, unless there's something I'm not understanding about the physical connection of the board Nd the membrane.
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Personally, if it comes down to spliting the "frame assembly", I'd say go ahead and get a replacement 'board.
Your work will not be in vain regardless.
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Is there a way to do this without separating the black tray and cutting all the rivets? I can see the ribbon like connector at the bottom, but the angle prevents me from accessing it without bending/breaking the main board, unless there's something I'm not understanding about the physical connection of the board Nd the membrane.
The mainboard is screwed into the keyboard frame and the steel plate. Look carefully for screws and undo any you find. Then you should be able to re-connect the keyboard unit.
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I'm pretty sure I've got it fixed, about to reboot and test. I was able to angle the PCB out as in the pic above and slip it loose and back into place. Also testing my new (to me anyway) NMB RT8756C+ tonight. Should be some pics to come later.
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It's ALIVE!!!!! Thanks to everyone for the help. Expect some photos of the M and the new board in the pics thread soon. Special thanks to ripster for sticking with me through this thread!
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I'm glad to hear it's working! Good luck with it!
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sweet :D
congratulations!
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Speaking of the PCB: does anyone have a spare? At some point I pulled a keyboard apart for cleaning and to paint the case and the PCB is nowhere to be found...
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What part number is the keyboard?
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:lol: I don't know and I have no way of finding out, since I painted the case hot-rod red - which means I painted over the label. However, I think any 'standard' Model M PCB should work.
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Well, if you have a Unicomp or 42H1292 (i.e. controller slots into the keyboard assembly - like the one above) You'll need a different type of controller to the regular one. I actually have a spare Unicomp controller lying around which I think is still operational.
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This one is the standard IBM Model M deal with the two ribbon cables.
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The only Model M controller I have is an M5-2 controller, and that's in my keyboard!
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What an odd place to keep such a thing!
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It's just like keeping a floppy drive in a computer!
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The only Model M controller I have is an M5-2 controller, and that's in my keyboard!
You say that like it doesn't come out...
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It's just like keeping a floppy drive in a computer!
Like how my GF keeps my balls in a safe... wait.
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It's just like keeping a floppy drive in a computer!
That's a sure fire way to get a "Non Sytem Disk" error.
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Shawn, are you at T.A.D.?
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That's a sure fire way to get a "Non Sytem Disk" error.
Only if there's no non-bootable floppy disk in the drive!
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Boot disks. Good times, good times.
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Shawn, are you at T.A.D.?
You, sir, have some sort of sea service exposure (Marines or Navy). In the Army, it's TDY.
And, no, I'm home. I got back in February from Afghanistan.
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LOL I was in the Army and stationed there for a few years - 87,88,89. Quite a cushy assignment.
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Oh, you said 'at' T.A.D., which means it's a location, not a status. I've never heard of it, where is it?