I am working on a Takky, after successfully getting a Mystic to go. I been working on a 6420/180 Sonnet Crescendo G3/400 Power Color Classic and it works great (Sonnet Trio and ATI64 PCI's) running OS 9.22.
In trying to upgrade the 6420/180, I just bought a 6500/275 and installed in the CC. Everything works but the PCC screen remains black. The PPC external monitor works fine (ATI 64 PCI card) and the same black screen is produced with or without the PCI ATI card. This motherboard works perfectly when it is back in the tall 6500 case and again produces a black screen on the PCC. The PCC works normally when the 6420/180 board is back in place.
I've read everything I could find on the web, including the 12 pages of the previous installment of this color classic forum, and could not find any difference in the VGA sensing or wiring between Alchemy and Gazelle that would produce this effect.
Does anybody has seen this before and/or have any suggestions?