Not sure if you managed to fix the issue with your Mac since last year but a maxed out 9600 with 1.5GB of RAM takes 4 minutes to complete the initial RAM test before switching on the screen. It may look like video is not working but it just takes that long before the computer actually starts booting after testing the RAM. I have the same issue with my 9500. You can disable the RAM test with MacOS 9. I think you need to press the Option key while opening the Memory control panel.
