OK, just to satisfy all curiosities I went through the entire procedure outlined in the til article, zapped PRAM, restarted with extensions off, dumped prefs and restarted.
What happens when I zap PRAM is the main monitor doesn't light up at all and the system loads on my second monitor (which is usually off). So after all the messing around and resetting monitor prefs I'm back to square one.
QUOTE
On earlier computers, the resolution is stored in PRAM and is read at system startup time by the video driver in ROM. Later versions of Apple Displays software rely on a preference stored on the hard drive to set this resolution instead of the PRAM setting. This preference is read during the startup sequence, and is applied either during system startup time, or when the Finder starts up, depending on the video controller.
Different video cards and built-in video handle resolution preference loading at different times, depending on when the driver for the video card and built-in video is loaded.
What usually happens is the startup screen is at 800x600 res until the ATI extension loads then it switches to the selected res (1024x768) for the rest of the startup process. Only difference I noticed after zapping, etc. is the res didn't switch until just before the desktop loaded. I haven't restarted again to see if the switch of res goes back to it's former point.
It's not a matter of selecting unsupported resolutions either as the card supports up to 1920x1080.
Nonetheless the screen remains dark unless I turn off the monitor and then turn it back on. The second monitor loads a pattern OK but it's not the one chosen for the system. I'm afraid it's just some anomaly with the video card (Original Mac Radeon 32 MB) combined with that particular monitor (Mitsubishi Diamond Plus 91).