I have gotten a old B&W G3 motherboard, CPU, ATI Rage and some RAM. I cut the -5 volt on the ATX powersupply, and I am using the little power button on the motherboard (behind the 64bit PCI slots) to power on the system. A few LED's on the motherboard come to life, but I get no boot chime or any display. Any ideas? I have no drives hooked up at this point, I did try a USB keyboard to see if that was needed to boot, but no go. Thanks
It is possible that the G3 board and expansion cards do not draw enough power from the ATX psu. If you hook up a hard disk and/or CD ROM to the board, they should draw enough power to keep the ATX psu fully alive.
Also try resetting the CDU switch and/or removing the PRAM battery. Check the PRAM battery voltage too. No keyboard should be required for the G3 board to boot.
Phil
Do the B&Ws still have the MAC-ATX jumper? If so, make sure to change that.