Unicomp Model M: Spill--No Longer working properly

[DarkTiger8929]

I have a Unicomp Model M and I accidentally spilled beer into the keyboard.  It spilled directly into the numpad and onto some of the arrow keys.  The majority of the letters no longer work at all, as well as 1 of the numpad keys and some of the arrow keys.  However, when plugged into the computer, the Numlock lights work, the computer recognizes it, and a few keys still work correctly.  I took the front and back off the keyboard, removed the PCB and cleaned its contacts as well as its socket.  Being new to the model M world, I don't know much about them.  As far as I can tell though, there isn't a way to take the metal backplate off the back of the keyboard to clean the switches (as it is held on with melted plastic blobs).  I was referred to you guys for assistance.  What course of action would you recommend?

Thanks,
Matt Barszcz

[iMav]

Between the plastic and back metal plate are the membrane switches.  They likely got beer on/in them.  You can remove the melted plastic blobs, you'll just need an alternative method of putting it all back together (small screws/nuts would work).  At this point, it is likely a loss, so you have nothing to lose.

[bhtooefr]

Ouch.

My guess is the membrane is contaminated. However, repair should be fairly reasonable, IIRC - Unicomp quoted me $60 for a Model M13, but that's because the TrackPoint section is no longer being produced for any keyboard.

[bigpook]

Yeah, but a new unicomp is around 60 dollars anyway. He may be better off just buying a new one.
If the membrane is contaminated, does that mean that if he cleaned it, it would work?
It would be a bit of work to do but it may be worth a try. As long as he has the time and the inclination to do it.
I have never taken a model m apart to that point before. I think there are multiple membrane sheets, and then theres the  springs and hammers to deal with.

[bhtooefr]

Right, but the number I've heard quoted is $35 for a regular Model M. Doesn't hurt to try contacting Unicomp, to see what they can do.

[bigpook]

Right, but the number I've heard quoted is $35 for a regular Model M. Doesn't hurt to try contacting Unicomp, to see what they can do.

By all means, a phone call to Jim Owens will straighten that out. : )

[DarkTiger8929]

Thanks to everyone for the quick replies.  I think I may try iMav's idea of taking off the plastic blobs and bolting it back together if it comes down to it.  Do you think there would be harm in giving the model M (minus keys, minus PCB, minus case) a bath in an isopropyl/distilled water mixute?  Let it soak a while, swish it around, let it soak some more and then leave it out to dry?  Perhaps that would dissolve any corruption on the membrane without having to tear it apart (and try to get it back together)?  Think there's any harm in trying it?

[iMav]

At this point, there isn't harm in trying anything.

These keyboards have been known to survive dishwasher bathes...so I assume as long as you give it a LONG time to dry you'd be fine.

[lowpoly]

Between the plastic and back metal plate are the membrane switches.  They likely got beer on/in them.  You can remove the melted plastic blobs, you'll just need an alternative method of putting it all back together (small screws/nuts would work).  At this point, it is likely a loss, so you have nothing to lose.

There is a site somewhere that explains this in depth. Anybody got the link?

[bigpook]

This may help

http://sandy55.fc2web.com/keyboard/repair_model_m.html

[lowpoly]

That was the one I was thinking of.

[pex]

Think there's any harm in trying it?

There's rust/corrosion risk if you're not making a full dissembly.  Since I don't fully understand whether your suggestion about bathing precedes full dissembly, I would suggest no good would come from soaking a 'it's too much of a pain to remove the plastic knobs' assembly.

Know that if you've rusted/corroded electrical pathways and not just gobbed them up with yeast, you can probably try sanding/wooling them or creating replacement paths with aluminum foil.

[itlnstln]

The best cleaning job I ever did on a Model M was about 15 years ago, or so, when my dad and I took several apart and soaked everything (except the PCB, of course) in Simple Green.  In any case, though, we fully disassebled the keyboard.