I'm trying to upgrade the graphics card in my Power Mac G4 (dual 1.25GHz, AGP graphics, non-FireWire 800, OS 9 capable) but I'm having a bit of trouble. It currently has an ATi Radeon 9000 Pro (or whatever the hell it is) with 64MB of video memory. I've got a couple of faster AGP cards I could put in, both ATi Radeon 9200s or something similar, each with 128MB of video memory, though one of them is known to be slower. I've tried both cards in the Power Mac. The Power Mac wouldn't even turn on with them installed properly. Then, while I (foolishly) was trying to remove the card with the machine still plugged in (at this point the card wasn't seated 100%, but still could have worked in any other system), it turned on, but there was no Mac boot chime, it beeped loudly once and the fans ramped all the way up for a few seconds, then it sounded like it was running normally. Then, the boot chime came in, but I got nothing on the display. I took out the upgraded card and verified with the old one that the system is still fine. The system behaves the same way with both of my Radeon 9200s. I should mention that both cards came out of Windows computers, and aren't Apple-sourced. I was wondering if anyone could shed some light on this issue.