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geekhack Projects => Making Stuff Together! => Topic started by: Unxmaal on Sat, 05 August 2017, 16:26:21

Title: [Help] IBM Model F PC 83 issues
Post by: Unxmaal on Sat, 05 August 2017, 16:26:21
Hi all!

I just got my IBM Model F PC 83 functional for the first (for me) time. I connected a Teensy 2.0 and used Soarer's latest firmware.

Unfortunately, I'm having problems with a few keys. The keys' flippers appear to sometimes 'stick' in a down position, meaning they'll actuate the keyyyyyyyyyyyyys until I manually unstick them.

What's the process to fix this? Should I do a full teardown, foam replacement, sandblast, respring, and so forth? Where's the best guide for that?

Thanks!
Title: Re: [Help] IBM Model F PC 83 issues
Post by: fohat.digs on Sat, 05 August 2017, 16:54:54
First, I would pull the key and re-seat it. Maybe jiggle things like the spring around a little bit.

Look for something that might be dirty or sticky somewhere.
Title: Re: [Help] IBM Model F PC 83 issues
Post by: Unxmaal on Sun, 06 August 2017, 10:49:02
Looks like the foam mat disintegrated and got sticky dust all over the PCB. I've torn it down and will replace the foam.
Title: Re: [Help] IBM Model F PC 83 issues
Post by: Unxmaal on Thu, 10 August 2017, 19:49:20
I've done a complete and total teardown and rebuild of this board.

https://imgur.com/a/M7TBV

Unfortunately I'm still having a few flippers that "sometimes" don't seem to actuate.

Currently, they're all working, except for F10, but this seems to change if the board gets moved around.

Any thoughts or advice on this?
Title: Re: [Help] IBM Model F PC 83 issues
Post by: Unxmaal on Wed, 16 August 2017, 14:07:47
Since I'm the only person posting here, I'll answer my own question:

This happened because the springs for buckling spring keys are really, really picky about being in the correct "spot", inside the cap.

For each key that was "stuck", I reseated the cap, sometimes several times. Eventually the spring settled in the right place, and the key tested properly.