[ed010]

When I start my G-5 using the option key on startup, so I can choose a different disk to boot from, I get no output to my monitor. They are blank , black, nothing., The machine boots perfectly otherwise. This started when my old Acer X241W monitor died I replaced it with a AcerX243W. The only thing that has changed is the one monitor. I tried disconnecting and booting with only one monitor but the exact thing happens when I hold the option key on start. It makes the start up sound and other noises like it is booting but the monitors are blank.
As far as I know there is no driver that has to load for the monitors to work or am I missing something?
All suggestions welcomed

[P]

Most likely the default resolution is one that your new monitor does not recognize. Once the bootup procedure gets going, it switches to some other resolution and you're fine.

You might be able to fix it by resetting the PRAM (holding command-option-P-R when pushing the power button, then releasing once you've heard the bootup sound twice).

[ed010]

Thanks for the helpful suggestion. I tried that but as I discovered that wasn't the problem. I had a Radeon 8500 in the AGP slot that was becoming unstable so I had switched both monitors to a second video card in a regular PCI slot. Apparently the AGP slot has priority and the other PCI slot only produces output after booting if there is a card in the AGP slot, with or without anything connected. I simply removed the offending card from the AGP slot and the problem disappeared. The start with "option" now works as expected. Moral of the story is to remove non working peripherals from the system even if nothing is connected to them.