I've stumped myself with this II+ (clone)
It was working fin until today when it failed to start. The screen shows some bands of lo-res graphic horizontal bars. No beep.
I've removed all the cards and the top 32K of RAM, so it is sitting with only the lower 16K of RAM.
I am getting a clock signal, the 14 MHz, 7MHz, 3 MHz and 1MHz are all there.
All address states at the CPU show logic state high, so that's good.
The only thing peculiar is that Data lines D0 and D2 are at logic state low - the rest of the data bus lines are logic state high.
This is both at the CPU pins and at the RAM pins.
I'm thinking they should all be high. There is no differece with or without a CPU connected, but I've verified that the CPU is good in another machine.