I think I figured out the screen issue, apparently the G4 mini doesn't like some kinds of high res screens or something or other. Problem appeared on a newer 1920x1080 22" monitor, I have it hooked up to an older 1280x1024" 15" LCD and it seems to be fine now. :?:

fan isn't running very fast maybe that's an issue? I feel warm air coming out the back.

no temp probes inside (weird) only get HDD temperature, it's at 43C