Videopac / Odyssey2 forum

Videopac / Odyssey2 => Hardware => Topic started by: kokkiklhs on June 08, 2018, 07:53:17 AM



Title: Bad keyboard membrane
Post by: kokkiklhs on June 08, 2018, 07:53:17 AM
I recently acquired a Videopac C52 (G7000) from feebay in great shape and with a couple of games, but stated as "powers up well but keyboard non working".
Of course I imagined that it would be easily fixed and (of course, again) I was wrong! :D

It is NOT a problem with dirty contacts on the board's connector, NOR bent/badly attached/torn edge of the ribbon, NOR bad 74LS of the keyboard controller circuitry...

The problem is the membrane itself. I detached it and found out that the glue that holds the 2 foils together has gone corrosive due to age and has destroyed the conductive continuity of the traces INSIDE the membrane in a million places.

As I reckon that there aren't any spare new membranes around to buy (or am I wrong???) and I don't want to butcher another machine just for the membrane, I thought of *trying* to restore the traces one by one using a DIY mix of graphite powder and glue and "painting" them over the bad ones. I really don't know if this will work out, but I will give it a go!

Stay tuned, the project will take place sometime within this summer and I'm really ambitious, even though I usually get disappointed at the end with such situations! :D

Has anybody a similar experience or any other suggestions to share? It's the first time I see something like that...


Title: Re: Bad keyboard membrane
Post by: gertk on June 13, 2018, 06:17:44 AM
There are several kinds of conducting glue for sale, the best and most reliable is the Bison elektrokit (which contains pure silver).
I managed to repair some traces of an Amstrad CPC 464 keyboard with the cheaper (black) conductive paint found on eBay but for the (bendable) cable part I had to use the Bison stuff.



Title: Re: Bad keyboard membrane
Post by: kokkiklhs on June 13, 2018, 01:15:09 PM
There are several kinds of conducting glue for sale, the best and most reliable is the Bison elektrokit (which contains pure silver).
I managed to repair some traces of an Amstrad CPC 464 keyboard with the cheaper (black) conductive paint found on eBay but for the (bendable) cable part I had to use the Bison stuff.

Thank you for this info! I already know some of these products that are being sold, the one with the silver is pretty expensive (however most effective), but I think I'll go for the DIY option I described above, for 2 reasons:
a) It's practically for free, no cost at all
b) For the fun of it, and for the experiment/experience!

In case this doesn't work out, I'll go for a more "professional" solution, as you suggest!
 8)