Thanks for the advice... I will open up the cabinet tomorrow and try this. The picture I posted is a little misleading, because you can't see how bad the black levels are.... it is like the blacks are light grey instead of black. When I set my regular pots to their old levels, the picture is so blurry that text is unreadable.
Do you have any idea what could have caused this? Upon further investigation, my cabinet is displaying other weird behaviors... the fluorescent light in the marquee wasn't on when I discovered it today, but works intermittently when I jiggle it - the bulb is dark gray on one side now, so I guess I'll replace it. I also noticed that my arcade buttons (hooked in through an ipac controller and then into a USB port on my PC) were not responding until I rebooted the PC. They were fine for a while, but then stopped responding after another reboot. All of my devices are plugged into a "smart" power strip, that is supposed to cut power to my monitor and marquee light when the PC is shut down.
I'm afraid with all these sudden weird behaviors that I may have some lightning damage or something. Does this make sense? I am so mystified by this combination of sudden issues.
One more question... where is the neckboard? Sorry for the newbie questions... your help is much appreciated!!!