Hi,
I might help you
My setupSo please tell me :
0 - Go to the Grex unofficial site and use the LASTEST Firmware without pluggin any card on the PCi bus !! Put 64mb at least.
1 - how do you power it ? AT or ATX PSU or by the floppy connector on the motherboard (don't do that !!!), or by the old amiga power connector (don't do that too !!!). Try to check the psu connectors when the machine is 'loaded'.
2 - Is the link between the BPPC/module/GREX are all 3 perfect ?
3 - Is the link between the BPPC/module done by metalic screews ? (ground + securities for the connector)
4 - Does your PCi cards are deeply plugged in theirs slots ?? I had a joke with cards in time even on PC :crazy:
5 - What kind of Grex1200 do you have ? do you have the label "Neue Edition" with red wires like mine ?

or is it an updated model with some green wires ?
6 - which cards did you try and which order do you put them ?
My suggestion :
PCI control menuOn the 1st slot (closest to PSU connectors), Network card, then Sound Card, and in the last slot the Voodoo3
But when you press the ESC at startup you must get the BPPC menu with a voodoo3 and permedia2 card.