28318Repair of MARCH Commodore PET 2001 chiclet keyboard
- Nov 29, 2012I am working on getting MARCH’s Commodore PET 2001 chiclet keyboard working again. There were some keys that were not working.I disassembled it and cleaned it. But some of the keys still didn’t work properly. I noticed that some of the keys had something metallic on the bottom of them and others didn’t. It appeared to be random. Talking to Dan Wobser and to Ian Primus, I found out that the rubber in the keys is a sorta conductive silicon. My suspicion is that this silicon becomes less conductive over time or is not reliable to being with. It seems that the previous owner had fixed some keys by adding some metal to the bottom of the keys. I’m not sure what kind of metal it is.When I replaced one of the keys with the thin metal on the bottom to previously not working key, then it worked.I have had a devil of time trying to find info on repairing Commodore PET 2001 chiclet keyboards. I find other info, but nothing specific about what I am looking for. I looked on vintage-computer.com, but I have not found anything useful.Mike Loewen suggested this:
http://store.caig.com/s.nl/it.A/id.1626/.f?sc=2&category=41But they require a minimum order of $25, so I don’t want to buy three of these $9.99 things.I posted this on cc cmp and got this response:>Maybe he used something like a 3M 3311 foil tape?
>I'm not sure how well the adhesive would hold up long term since it isn't>intended for this application, but it is still very cheap.
>Another option might be a foil tape that is madefor electronic/EMI>shielding applications.>http://solutions.3m.com/wps/portal/3M/en_US/AdhesivesForElectronics/Home/Products/EMIEMC/ShieldingFoilTapes/
>Something like the MG Chemicals 8339 rubber keypad repair kit might also>work if these buttons are using a conductive carbon contact. (I personally>preferred the older pre-RoHS version with the 3 small bottles though.)>http://www.mgchemicals.com/products/prototyping-and-circuit-repair/circuit-repair/rubber-keypad-repair-kit-8339/
href="http://www.amazon.com/MG-Chemicals-8339-Rubber-Keypad/dp/B0081SGM8M">http://www.amazon.com/MG-Chemicals-8339-Rubber-Keypad/dp/B0081SGM8MThere are some local distributors of this 8339 rubber keypad repair kit:
Electronix Express 900 Hart Street, Rahway, New Jersey 07065 Phone: 732-381-8777
Wayne Electronics 637 Route 23 South, Pompton Plains, New Jersey, 07444 Phone: 973-839-5888
Interstate Electronics 1394 State Route 36, Hazlet, NJ 07730 Phone: 732-264-3900
Lashen Electronics Inc. 21 Broadway, Denville, New Jersey, 07834 Phone: 973-627-3783
Green Brook Electronics 269 US Hwy 22, Green Brook, New Jersey, 08812 Phone: 732-968-3500
Fax: 732-968-3378I plan on going to the one in Hazlet on Sunday to pick it up.I still wish I knew what kind of rubber the key was made of and what the metal foil is made of that was added to the bottom of it. It could be silver for all I know. It is very difficult to find specific information about this keyboard and it’s material and repair.Jeff Brace
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