Model M: malfunctioning key due to broken rivets? How sound is my repair plan?

[Vanilla]

So I recently got my hands on a previously untested model m spacesaver and to my surprise all keys work without a hitch except for the left shift button.

Pressing that specific key does not result in a tactile click nor registered input. It is only when I bottom out the key completely for the key to produce an output.

Taking the key off, it appeared the spring had corroded and broke at the point it meets with the hammer. The hammer is in good condition. *I believe this is the reason why the key does not click.

Upon taking the casing off, it appears just the rivets on the left side, right under the lower left side of the keyboard were broken. *Might this be the reason why the left shift key requires me to bottom out the key for it to work?


Seeing that this is only 1 key, I dont think it's necessary yet for me to go all out and de-rivet the majority of the still there rivets and bolt mod this keyboard.

Here's my train of thought as far as repairing this single key: buy spring and hammer assembly from unicomp, use just the spring from it to replace corroded original one with tweezers. (I already tweezered off the rusted stump of the original one off)
After being disassembled and with the internals clamped down, epoxy the missing rivet holes on the previously mentioned lower left corner.

How does this sound to you guys?

[fohat.digs]

Some people swear by replacing springs ("The Chopstick of Death") but I have never tried it.

You should use self-tapping or machine screws to secure broken rivet tops - not glue.

[jdcarpe]

Some people swear by replacing springs ("The Chopstick of Death") but I have never tried it.

You should use self-tapping or machine screws to secure broken rivet tops - not glue.

I successfully performed the "Chopstick of Death" repair on an AT Model F after I asked you about it. Is it as perfect as a factory placed spring on the pivot plate? Not quite, but it works well, and you probably couldn't differentiate it from the other keys, if you didn't know which one it was.

[E TwentyNine]

Taking the key off, it appeared the spring had corroded and broke at the point it meets with the hammer. The hammer is in good condition. *I believe this is the reason why the key does not click.

If the spring got that corroded it's possible there's damage to the membrane.   If you're certain all the other keys work, and the CapsLock and Left Ctrl key work fine, I wouldn't worry about a bolt mod just yet.

Before you order anything, work with what you have.  Pull a spring from a key you can live without for now (something from numpad, or scroll lock), and try to replace the broken one.

If it works you're golden and can order the part.

[mougrim]

By the way, maybe you'll think about bolt mod? It's will make your keyboard quite future-proof.

[Vanilla]

Thanks for the replies guys!

As it stands, I have yet to have tried swapping over a spring from a negligible key, I'll get BBQ skewers tomorrow to do so.

Regarding possible water damage, there's no hint of corrosion from a possible spill in the past on the metal plate, however there's a tiny bit of mold on the back label, which leads me to think of moisture or of a minor spill in the past that wasn't entirely dried up as the culprit. From random removal of keys, of which included the entire leftmost column, it only appears it was this key that had a rust issue. I'm as perplexed as you guys are.

As for a full on bolt mod, I'm still considering, although I have time constraints and the lack of tools as a student a couple states away from home and his father's arsenal of tools.
Not to mention the fear of the potential of "messing up" with what would be his *first* bolt mod on what unfortunately was a space saving m. Reason of which I'm here asking! 


At the moment I'm still considering my options; I could live with using my right hand to hit the shift key but old habits are hard to kill.


I've also been in touch with unicomp; for them to repair my m. Their price seems really fair but I'm not sure what they're going to do when they mention they're going to refurbish it to the point of "good as new". I might end up starting a thread asking members for their experiences with this program of unicomp's.

[Vanilla]

Just an update for you guys,.... the chopstick of death trick worked!!!!!

I borrowed the spring from a lesser used key and transplanted it to the problem left shift key, as suggested by E-29 and low and behold it worked! Good as new!

Thanks again you guys! Saved me the trouble of having to do a bolt mod.

[mougrim]

I've also been in touch with unicomp; for them to repair my m. Their price seems really fair but I'm not sure what they're going to do when they mention they're going to refurbish it to the point of "good as new". I might end up starting a thread asking members for their experiences with this program of unicomp's.

Basically they're going to replace matrix and all springs/hammers assemblys by one of their manufacture (as I heard) and re-done all rivets.

[rowdy]

Just an update for you guys,.... the chopstick of death trick worked!!!!!

I borrowed the spring from a lesser used key and transplanted it to the problem left shift key, as suggested by E-29 and low and behold it worked! Good as new!

Thanks again you guys! Saved me the trouble of having to do a bolt mod.

Thanks for the update!

I like happy endings

[E TwentyNine]

Just an update for you guys,.... the chopstick of death trick worked!!!!!

I borrowed the spring from a lesser used key and transplanted it to the problem left shift key, as suggested by E-29 and low and behold it worked! Good as new!

Thanks again you guys! Saved me the trouble of having to do a bolt mod.

Great. Always try the simple stuff first.