Easier solution is to apply some conductive light lube. Radio Shack used to carry it, and I repaired a LOT of remote controls with it!
Cindy -----Original Message----- From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Peter Coghlan via cctalk Sent: Wednesday, April 25, 2018 4:17 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Restoring rubber keyboard on a logic analyzer > > I have a Philips logic analyzer (PM3585) which is about 20 years old at this point. It seems to be basically functional except for the keyboard, which unfortunately is a critical part. > > This is one of those molded rubber type, with a circuit board behind the rubber that has contact areas made of carbon film (at least they are black in color) and on the back of each key a small cylindrical bump also coated with carbon. Some of the buttons work but most don't seem to even if I press hard. > > I've disassembled the keyboard, which was easy enough. Inspection shows no damage and no signs of corrosion or contamination. I wiped everything with isopropyl alcohol anyway. The result is no change in behavior. > > Any suggestions for what to do next? > I had a similar problem with an old VCR remote control. The problem seemed to be that the bumps on the back of the keys lost their conductivity (and cleaning them made them worse). My solution was to glue pieces of aluminium foil to the back of the keys. It was tedious but it seemed to sort it out. Regards, Peter Coghlan. paul --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus