Well, I finally got tired of the dead B&W sitting on the floor, so I started checking ebay for a replacement motherboard. I ended up scoring a Rev. 2 B&W motherboard (with 300mhz CPU) for $12 and change with Free Shipping.

After confirming it worked with a minimal config, I decided to try the G4 upgrade again. One change, though, this time I went with the NewerTech enabler (from OWC) rather than the XLR8 one.

So far, so good... it booted from a Tiger install and a reports a PowerPC G4 @ 300mhz. Next step is to fix the jumper block, put back in the rest of the RAM and PCI cards and do a clean Tiger install. (Not sure if I didn't strip the G4 code from parts of the current one.)

At this point, I'm not quite sure what happened the first time. My personal theory is that one of two things caused the problem- either the XLR8 enabler or the Rev. 1 motherboard. My gut feeling is that it's the Rev. 1 motherboard, though... probably some minor component which failed with the load of the G4 (back to the power supply comment).

FWIW, if somebody wants to tinker with the partially dead Rev. 1 board, shoot me an address and a couple of bucks for postage and it's yours.

John