Small setback
Posted by Trixter on January 20, 2008
The 5160 (PC/XT) has gotten significant use this weekend; not only was I finishing up the design docs for BeeperTracker (which Jason Scott is heavily lobbying to rename MONOTONE, which will ultimately prove successful), but Max was bored and we spent time playing old games on it. Unfortunately for me, the use was significant enough that the keyboard’s spacebar stopped working. Normally I’d whip out another one and keep going, but this was, in fact, my last 83-key keyboard that had a functioning spacebar. I pried all of the keys off and cleaned out all of the gunk… only to find that the spacebar doesn’t go back on the way it came off, as there are two metal prongs that need to fit into holes.
I’m terrified of taking the plate off of the back (buckling springs everywhere!) so I’ve asked the Classic Computer Mailing List for a more official way to repair it. Until then, I’ll be playing Half-Life: Episode 2.
Oldskooler Ramblings 
phoenix said
Doh! Alt-32 man, Alt-32! :)
phoenix said
Oh, and Monotone is a great name. This reminds me, I made a BBS intro for a school friend in QB, back in the day, which used chains of Sound commands to make something that vaguely resembled music. I’m hoping they’re still on my 20GB HD.. I still have to copy my QB stuff off it sometime.
Trixter said
If I use alt-32 then my ALT key will break!!
I got advice on how to fix it from someone I revere as a demigod on fixing old hardware. Hopefully he won’t mind me reposting it here (thanks Tony!):
The only way I’ve found to reassmble them is to take the whole thing
apart. it gives you a chance to properly clean it anyway.
1) Remove outer casing and keyboard cable.
2) Remove all keycaps apart from the spacebar (if it’s still in place)
3) You mention a bent-over tap. This is, IIRC, on top of the keyboard,
and it’s prrety clear it’s been bent after assembly. Bend it back to
clear the slott in the other part of the kayboard.
4) Slide the bottom section relative to the top to free it. With the
keyboard upside-dwon, lift off the lower part complete with the PCB.
5) Remove all 83 spring/flap units. They’re all identical AFAIk
6) Remove the space bar if it’s still in place
7) If you want to, you can remove the PCB by undoing the earthing screw,
then sliding it to free the keyhole slots from the studs on the base
plate. There’s a thin plastic insulator under the PCB, don’t lose it!
8) OK, now time to putit back togther. Fit the PCB to the base and screw
down the earthing screw. Put the space bar back on and hook the wire
linkage the prevents it from tipping in place. Then pull the space bar up
as far as you can without disconnecting this linkage.
9) Fit the flaps, taking care to ket the space bar one correctly
positioned. Fit the base/PCB and slide it over to lock it. Don’t bend the
tab yet. Prese the space bar down so it clicks in place, and check it
clicks and returns properly. If not, you need to take the baseplate off
again and have another go.
10 Fit the other keycaps, getting the springs located properly. Again
check eack one clicks and returns if not, Pull that keycap and try again.
11) Fit the cable and plug it into a PCB. Try the keyboard. If it doesn’t
work, you might have to go through the whole process again, but most of
the time they do work
12) Bend over the locking tap, refit the case.
Some random guest not really named "Per" said
How often do the keys at the 83-button keyboards break?
and
How mutch can they handle before they break?
and last
How do they break?
Trixter said
“How often do the keys at the 83-button keyboards break?” Hardly at all. In fact, this is the first one I’ve had broken (although I am pretty good to my keboards).
“How mutch can they handle before they break?” Isn’t it best to not find out?
“How do they break?” Most commonly the keycaps snap off at the stem, due to extreme physical abuse (ie. smashing it). Less commonly, the buckling spring mechanism underneath the key will fail. In my rare case, something is wrong with the PCB underneath the keycaps/springs, even though I’ve gone over the board with a magnifying glass and multimeter.
Can’t find the problem, so I’ve thrown it in the spare parts bin. I was able to fix my other XT keyboard, so I’m back in business.