I have a Williams Flash that is no longer able to boot up. The onboard diagnostic LEDs remain on after a restart. I've taken the boards out and have created a bench setup for them with +5v & +12v and what I'm seeing is that the reset is coming to the CPU as expected, but the 6800 CPU looks to be acting a little strange. What I'm seeing is that the 6800 address and r/w outputs are in a tri-state, but the data output bus is being driven low. I've confirmed that the halt (active low) is high and the TSC (tri-state control) input is low when measured at the pin which is what I'd expect. The IRQ input is toggling, but I'm assuming that is as expected. The oscillator inputs look to be toggling.

Have you guys seen any funky behavior like this before?

It doesn't seem like the 6800 is coming out of reset and accessing the ROMs. I even tried with Leon's rom in IC17 and nothing.

I'm tempted to buy a replacement 6800, but I want to do more homework first.

I have a firepower, but the system6 looks to be using 6802/6808 and it doesn't look completely backward compatible, otherwise I'd drop it in.

Let me know if you all have any advice.

thanks,
Chris

Good call regarding checking the socket. I replaced all of the original sockets from the ROMs long ago when I replaced the board connectors, but I just checked and the CPU appears to have it's original RN socket which I read aren't the best either. I'll go ahead and swap that socket out as it's probably a good idea regardless.

thanks,
Chris

After replacing the socket the same issue persisted. As a last-resort I went ahead and ordered a new 6800. I replaced the 6800 and to my surprise it was now booting and passing the on-board diagnostics!