Author Topic: 464 PCB Keyboard Repair: Remove plastic key sockets  (Read 1217 times)

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Offline rnlf

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Hi,

I'm restoring a 464 that is working perfectly fine, but when cleaning it, I found the keyboard's metal frame to be pretty rusty. I was trying to get the plastic sockets for the keys off without breaking them, so that I can remove the rust from underneath them. Any idea how to do this? It looks like they are made from a single piece of plastic gripping onto the metal frame from both sides.



It would be relatively simple to remove the rust between the sockets, but unless I also remove it under the plastic, it'll keep corroding and eat away the metal.

I can't find anyone on the web who seems to have done anything like that. Any hints are highly appreciated!

Offline rpalmer

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Re: 464 PCB Keyboard Repair: Remove plastic key sockets
« Reply #1 on: 12:42, 22 March 18 »
what does the back of keyboard look like.

The plastic housings may just be clipped in as that would most likely been the cheapest and quickest way to build the main part of a keyboard.

rpalmer

Offline rnlf

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Re: 464 PCB Keyboard Repair: Remove plastic key sockets
« Reply #2 on: 14:21, 22 March 18 »
I'll take a photo later at home. To me it looks like the back has the exact same width plastic around and I can't really see a seam.

Offline rnlf

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Re: 464 PCB Keyboard Repair: Remove plastic key sockets
« Reply #3 on: 10:36, 23 March 18 »
That's what the backside looks like:



It almost looks to me like the top and botton half are really only one piece. But I don't think that would be easily possible to produce, so I assume there must be some kind of trick...

Offline Gryzor

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Re: 464 PCB Keyboard Repair: Remove plastic key sockets
« Reply #4 on: 12:37, 07 April 18 »
I doubt it's only one piece? How would they produce that with the metal sheet smack in the middle? I would guess it's two pieces snapped together from each side...

Offline Bryce

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Re: 464 PCB Keyboard Repair: Remove plastic key sockets
« Reply #5 on: 11:02, 09 April 18 »
They push downwards out of the metal. However, it's old plastic and they break extremely easily, so I'd recommend you clean it without removing the plastic, otherwise you may be left with a completely useless keyboard. Small metal brush to remove the rust and then you can coat it with some black paint with a small paint brush.

Bryce.

Offline rnlf

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Re: 464 PCB Keyboard Repair: Remove plastic key sockets
« Reply #6 on: 10:03, 16 April 18 »
I ended up trying to remove the rust using vinegar and it worked fine... except it also removed the black paint/coating and created a mess of sticky brown residue, like rust got washed off but then settled again. I got rid of most of it by submerging the plate in alcohol and then rubbing, but some of it remained so I had to use a dremel with wire brush tip. It took me two hours to clean up all the stuff and I'm sure there's more under the plastic sockets. I call this a failure, but at least the plastic sockets were relatively resistant to the wire brush at low RPM, so I think the keyboard will still work fine.

I can't see any seams on the plastic sockets, not even with a magnifying glass, so I thought maybe they've been molded in place instead of in a separate process and then attached to the metal plate.

Thanks for the hints. Here's mine: Don't try to remove the rust with acid.

Bryce, it really looks like the sockets are wider than the hole in the metal on both sides. Maybe only slightly bigger on one side so that it can compress while they push it through? Anyway, it seems impossible to remove them without breaking them. That's very sad :-(
« Last Edit: 10:05, 16 April 18 by rnlf »