I have a 3003b CoCo 1 (the white one) with the melty keyboard. A few of the keys do not work. On a few of them, there appears to be a slimy substance that I've cleaned from the surface. The badge on the top of the case is mushy, so I can only assume someone used a cleaner on it and it got down into the keyboard.

This keyboard used folded mylar sheets with a separator sheet. I'll be taking the keyboard apart next week to inspect it. What's the best cleaner to use on these types without damaging the mylar or the material the traces are made out of?

  • 1
    The stuff I talk about in this answer works on keyboards. In fact, I used this very stuff on an original silver CoCo back in the 80s to clean out a keyboard. You don't need to take it apart, either. Just remove the keyboard and spray liberally letting the grunge and liquid drain out the sides.
    – user12
    Apr 30, 2016 at 0:50
  • @jdv - you should've posted that as an answer. Good stuff. Looks like Home Depot has the stuff in stock, too. Apr 30, 2016 at 13:06
  • Make sure you get the variety without lubricant. This bus for cleaning pots, but will make your keyboard a greasy mess! I'll spin off an answer today.
    – user12
    Apr 30, 2016 at 13:12
  • (ignore my typos. Doing this from a mobile)
    – user12
    Apr 30, 2016 at 13:22
  • @jdv - Used the stuff you recommended and it worked - mostly. I had to add a thin piece of felt under the keyboard mylar to get the keyboard fully working. May 12, 2016 at 16:18

1 Answer 1


The same stuff used to clean electronics mentioned in this answer (e.g., "CRC QD Contact Cleaner") will also clean contacts in computer keyboards. As discussed there, do not get the type used to clean and lubricate potentiometers, as this has a (surprise!) light lubricant in it. Still, an easy to make mistake.

The plain old contact cleaner found at hardware and electronic supply stores will do. Remove the keyboard from the case, and spray spaces between the keys liberally, letting the liquid run and boil out the various holes at the bottom and sides.

I've used this stuff to clean pop out of an original silver Color Computer in the 80s.

The OP used this stuff I recommended and it worked - mostly. He had to add a thin piece of felt under the keyboard mylar to get the keyboard fully working. Being as this was a common type of keyboard for the day, this addition might be helpful to others.

  • I would also add that keyboards where the rubber dome has carbon surface on the bottom to create contact with the conductive sheet - both sheet and that surface need to be cleaned, although it's unlikely this will get "dirty", corrosion and oxidation may cause issues. May 29, 2016 at 5:12

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