Mr. Macintosh
Member
I received my EPROM programmer and tested the existing ROMs in my 5170 against modem7's images for a type 2 board, and they were exactly identical. I think this rules out degraded ROMs as the source of my troubles. The W27E257's haven't arrived yet for me to make some Landmark ROMs, but I will report the resulting diagnostics (or lack thereof) when they do.
I am increasingly convinced that the problem I'm seeing is something much more fundamental than the ROM/RAM/CPU, but I can't be sure of that yet. The most heavily corroded component on the board when I received it was the MC146818P chip, and I know that it was powered on at least once with that high level of corrosion present. So perhaps some of it's surrounding circuitry was fried? I already went trace-hopping using the 5170 wiring diagram, and nothing was disconnected, so I also want to rule out trace rot.
I am increasingly convinced that the problem I'm seeing is something much more fundamental than the ROM/RAM/CPU, but I can't be sure of that yet. The most heavily corroded component on the board when I received it was the MC146818P chip, and I know that it was powered on at least once with that high level of corrosion present. So perhaps some of it's surrounding circuitry was fried? I already went trace-hopping using the 5170 wiring diagram, and nothing was disconnected, so I also want to rule out trace rot.