i'm not entirely sure, but i think the three pin header next to the cpu labled "pwr" might be a 5 volt supply to drive a CPU fan. kinda makes sence, but not entirely sure.
as you say your hard disk is drawing power from the zorro2 slot, it may be an idea to plug in a power line direct from the power supply, and see what that does.
As the 040 card might be drawing too much current for the hard disk to start up, or the hard disk and 040 might be drawing so much, that the system is not able to complete its diagnostics.
dunno, but just a suggestion borne out from previous expirience...
