IBM Model F AT key bounce (?)

[AndyJ]

I put the spare F back together with the extra barrels for the split shift, enter, and insert keys. I have a couple of problems, though:

1) the M key gives a "jm" (two characters) whenever it is hit. It does it on single keypresses, but not on repeat. No other keys do that. I've pulled and reseated the keycap, but no change. What would be a likely cause for this? A hair or lint under the flipper, maybe?

2) the spacebar is *way* louder than the Board #1. As in, obnoxiously loud. The stabilizers are properly set, the bar is steady and doesn't stock, and everything is fine except for the noise.

[AndyJ]

I took the sandwich out of the case, cleaned the ground connections, and reseated the connectors. No change.

I disassembled the sandwich, cleaned the circuit board thoroughly even though it looked okay, and reassembled the spacebar and carrier on my desk. Just as clinky-sounding, and much louder than the never-disassembled #1 board. It turns out the stabilizer spring is bent to make a "top" and "bottom". I flipped it over, and it had no tension at all.

Tentatively I'm going to assume someone bent the stabilizer spring to make it lighter. I have a third board I can take apart and check later.

Instead of bending the spring, I reassembled the sandwich without the spacebar, which certainly makes it easier to deal with the spacebar flipper. I popped a Model M spacebar on. It's loose and floppy, as expected, but I just wanted to give it a try.

The modelfkeyboards.com stabilizer clips I bought are apparently designed to be spot welded. I might try epoxying them in place just to see if it will work.

[Muirium]

Model F XT, right? I’m itching to edit the thread title.

[AndyJ]

F/AT. I have a lone XT hiding out in the closet, though.

Last night's experimentation ended with the reassembled sandwich sitting on the desk, ground lugs clipped together. The lights would flash when I plugged it in, but the computer didn't register anything. After that, the xmodmap remapping was gone. The logical next step was to reboot, but I was tired and went to bed.

[Muirium]

Thanks for resolving that.

(Any time I see a lonesome “Model F” show up in the Spy, I’m ready to merge that inevitable Ellipsesaver: Halp! question into his project thread. )

[AndyJ]

Ah, I forgot to update the thread. I decided to set the keyboard aside for a while, so I completely reassembled it so I wouldn't lose any parts. On a whim, I plugged it in... and the double-strike "jm" didn't happen any more.

I have no idea why it would make a difference for it to be in or out of the case.