Seems you've gone though most of the typical things.
You might want to measure you're getting a stable +3.3V out of the regulator as well.
Check it's actually sitting in the CPU slot correctly, it has to be pressed down quite hard along the length of the 200 pin connector to seat it properly.
You should check that the card definately can run with OS 3.0, I seem to recall that they needed OS 3.1 in ROM???
Sounds like it could be faulty though :-(
Someone (Hyperion?) are doing fixed price repairs on CyberstormPPC for 135 Euro, no charge if not repaired. I'm about to send 3 units away this week for repair.
Assuming you want to see the card again, probably not a good idea to send to DCE for repair :-P
