Does it look like the brightness is just way too high? Have you tried adjusting it already? I'm having a similar issue in which everyone is bagging on me for taking so long to fix it...here: http://forums.arcade-museum.com/showthread.php?t=177477
i had the chassis in a pole position and it had a white screen and then i put it a centipede and it works great maybe there is something wrong with the tube inn the pole position ?