Re: reset signal: That's an interesting case you pointed out (where the PIA dragged the reset signal down). Apparently it IS possible (with a bad PIA). I was referring to the design of the board.. The only component that should have the ability to pull reset low is the reset circuit and normally functioning chips on this board don't have the capacity to do so on their own (their reset pins are input only). Interesting that if a chip is fried in just the right way it can have the ability to drag it low on its own. You learn something new everyday!
It's worth mentioning that upon normal power up, the LEDs do flash and the zero shows up on the LED segment display. This occurs before the CPU starts executing any instructions. The first bit of code in any ROM should be to initialize the PIAs and that's when you see the LEDs and segment go out. The zero means nothing really. It is not the result of some test being performed in any of the pincoder ROMs, and I would also suspect is true for the Williams ROMs. It's just how IC33 and IC34 power up in this circuit.
Re: two minutes: Just to be clear, when you say "display" you are referring to the segment display on the MPU board, not any of the master or slave displays behind the backglass, correct?
From your test results above, it looks like your reset signal is high, but is it a STEADY high? Make sure your logic probe is set to PULSE and connect it a few seconds after powerup.
You should not be seeing activity on the address and data bus lines when using using 01b-bus (at least not after the first few microseconds after the reset goes high). Since you are, I'd say the CPU is constantly resetting and trying to run the ROM. Once it successfully runs the 01b-bus ROM the CPU goes into a wait state (not executing any more code) so the pins on the CPU (including address and data lines) should go to their states shown in the 01b-bus documentation (basically idle).
So, your board is either continually resetting because of:
1) Insufficient power
2) The reset circuit itself
3) A PIA is in fact pulling the reset circuit low.
In the case of 1) I have used a cheap 400w ATX power supply on the bench in the past. You should be fine. You should connect as many of the GND, 12V, and 5V pins of 1J2 as you can for more current flow. When you connect the driver board you should also supply power to 2J8 in the same fashion.
In the case of 2) the reset circuit is taking too long to finish its job (start low, wait ~0.5 seconds, go high)
In the case of 3) it could be possible that as the (bad) PIA warms up it lets go of the reset line, finally allowing the CPU to start executing code.
I'm not sure what the click you're hearing is. Hold your finger on the flipper relay after you power it up and see if that's it. With 01b-bus nothing is initialzed at boot - it does one READ from address 0000 and then goes into the wait state. This means that the flipper relay should do nothing at all under this test.
Edit: I've updated the documentation for the 01b-bus test so if this post still leaves you a little unclear download the beta release and review the document: