At times just randomly, all of a sudden my screen just turns white and stays there, sometimes for just a few seconds, sometimes I have to restart, any idea what's wrong?
Sounds like a video card problem, if a re-start solves it. Try connecting the monitor to another computer. If the problem persists then it is the monitor and needs to be replaced.
You need to figure out if it is the computer or display. I would assume it is the display and the problem is located in the video pcb. Plasma's aren't made very well in my opinion-if you have to have one, Pioneer and NEC are the way to go.