Welcome to MobileRead, aaronvegh!
If the problem is what I believe it is, we can help you easily enough. It's one of two things, a bad screen or (more likely) a really low battery.
You want it to be the battery, because you can fix that yourself as opposed to sending it in to Sony for a screen replacement.
What you do is plug it into the AC charger (can't do USB charging for this -- the 500 won't charge from USB if the battery is really flat), and leave it until the little red light above the power switch goes out (probably about 4 hours). Then see if the problem clears up.
Let us know if that takes care of it for you!
