since january, my monitor will randomly go black. i have a desktop ppc G4 from 2003. i tried replacing the cable but that didn't do the trick. i thought that perhaps it was the video card, but a few days ago when it went black i pulled the power cable out of the monitor and plugged it back in and it worked. but then when it happened tonight, it didn't work so i don't know what to think. i put in a new system drive tonight and all was well until i changed the monitor resolution. as soon as i selected the optimum setting, the screen went black. sometimes if i shut down for a few minutes and reboot, it will work.