I had to fix a couple of things... bad video cable, bad memory chip... but now it basically works with 2 exceptions:
- Some of the keys either don't work at all, work sometimes, or bounce (give multiple entries). The problem seems to be mechanical as the latches, the diodes and the board connectivity all seem to be working. Indeed, I was able to get some of them work by removing the key cap and squirting in some contact cleaner followed by compressed air. But this seems to be only a partial solution.
Any thoughts on how best to clean & restore the keyboard?
Alternatively, are there external keyboards available (most of the keyboard matrix seems to be accessible via connector J4)
- Since I no longer have an analog monitor or TV, I hooked the video input to an analog video->HDMI dongle. The problem is that the horizontal doesn't sync properly. It ranges from complete scramble to slow horizontal scrolling... I can usually remove the scramble and get a slow-horizontal scroll by switching back-and-forth between regular and reverse video (presumably this triggers the HDMI converter to try to re-sync). Note that the vertical sync pot on the board itself has no effect.
Any thoughts on how to fix the horizontal sync here?