What's weird about this machine is everything is "like new" except for the MPU board. When I looked at it, it appeared to have battery acid damage on it. But when I pulled it and took a closer look, it had been repaired. It had a new battery on it and the acid damage had been cleaned up and some kind of clear coating had been sprayed over the circuit board (almost like clear nail polish) to seal it. I ended up clipping the battery off anyway and installing a remote battery pack.
After checking out the machine and the voltage regulator and coils I fired it up and got one quick blink, followed by one flash on the MPU LED, and about half the GI lit up with a dead machine. This same thing happened when the owner plugged the machine in before I bought it (even though I asked him not to plug it in).
According to Clay's guides, this means the MPU self-test stopped at the first ram chip.... does that sound right? Looks like there's something wrong with the MPU board?