you could always try the old caps lock key trick. If you press it and the light keeps flashing the CPU has been found, but if after a few presses it stops flashing the CPU hasn't been found (The case for my A4000 anyway) Thr only times I've ever experienced the power light going dim (and flashing in my case) was when the Cyberstorm SCSI wasn't setup properly, or when my CybervisionPPC card slips out a little.
hope this helps
Robert
