[Coco] Trying to get a KoKo2 working

[Chris Osborn]

Thanks to Retro Canada I got a copy of the schematic and was able to test the PIA and the keyboard connector on the PCB and it's working fine. Pulled out a wire and jumpered the pins on the connector and I was able to "type". So it looks like the problem is entirely the plastic membrane inside of the keyboard. Is it possible it has become oxidized and if so, can it be cleaned? It has a black coating on all the traces and I had to scratch through it a little bit for the DMM probe to get a signal. I'm afraid of scraping it off though and having no trace left.