First of make sure the HD is healthy, try a different HD in your system or try your HD in a working SCSI system. Second thing that hit's me is that it might be heatproblems with your 040/40 and it's now giving upp after years of too hot conditions? Last thing is a blind shot in the sky but I've seen A3500 to have trouble with onboard fastram when a CSPPC was installed so try to just remove the fastram from the motherboard and just use fastram on the warpengine.
