PE 6600 DELL,tried all help topics in the above thread, battery reset bios ,know quite a bit on this mach. then replaced complete Io board reset bios replaced all drives removed raid card have new CPU mother board but old one shows OK new Io board no diff AGAIN start mach starts post using on board SCSI controller to run a channel . show CPU OK show SCSI cont ,shows all drives 8 on a ch ,.with out raid card b channel not shown on board SCSI is only one ch Again ,goes through drives then stops no floppy or CD picks up , Still cant enter setup to reset anything Can enter SCSI setup, but this is not needed at this time all DRIVES show OK as did before still will not finish post ???? ordered other internal parts to try other things BOB ???