iBook G3 stuck on white screen of death

I recently bought an ibook g3 500mhz from a really nice gentleman for a really good price. On the listing, he described the issue as the machine being able to chime and you can press caps lock however the screen remains white. At first, the issue seemed simple enough, probably a disconnected display cable, however, when I cracked it open I was surprised to see that the entire inner metal frame was coated with some sort of whiteish, powdery corrosion, presumably from a battery, it was basically snowing when it opened. And sure enough, when I checked, the display cable was still connected

So then the next thought process was that the corrosion was somehow causing a short on the motherboard but when I cleaned it off, other than a patch of corroded solder joints, the whole motherboard looked fine. And of course, that didn’t do anything, the screen still was white.

Item of note though, the hard drive will try to spin up twice before giving up

So right now I am really at a bit of a loss on what is wrong