The keyboard on my Franklin ACE 1000 suddenly started having dead keys. Working through the troubleshooting checklist in the SAMS guide, it became clear that the special capacitative-keyswitch IC had fried.
As a replacement IC doesn't appear to be available, I designed a replacement in KiCAD that uses CherryMX keyswitches and osiweb's Unified Retro Keyboard ASCII interface. I've yet to source proper replacement keycaps, so I'm using a random set I found on Taobao, but it is otherwise working well.
The KiCAD files are at https://github.com/ryucats/Franklin-ACE-1000-Keyboard and the relevant keymap code has been submitted to osiweb via https://github.com/osiweb/unified_retro_keyboard/pull/42
I have three spare boards if anyone needs one. Price negotiable.
Obligatory construction pictures follow:
Wow! This is pretty awesome! Keyboards are the big issue for Franklins dure to the deterioration of the Keytronic foam pads.
The foam pads can be replaced inexpensively with kits found online. (Or you can punch out circles of the foil-backed foam yourself).
One of the sellers is TexElec.com: "Foam and Foil" Capacitive Pads for KeyTronic & BTC Keyboard
Of course, the time and effort of rebuilding the keyboard is still considerable.
The replacement foam and foil pads from TexElec work great for repairing Franklin Ace keyboards! Slow work but easy. I only replaced the bad ones the first time. Then the others started failing with new use, so I suggest doing them all at once and it should be good a long time.
Yes, the TexElec pads work very well, and I used them when I first got this unit to make the original keyboard work.
Replacement pads don't help at all, however, when the 22-908-03A capacitance-to-TTL "selector" IC at Z10 fries. Hence this replacement keyboard :)