Hmm... definitely looks like some sort of contamination on the motherboard. My suggestion would be to remove the board from the base, get some isopropyl alcohol and lint-free wipes (if you can find some; paper towels might work but will probably rip) and clean off the "stuff". Pay particular attention to the (tiny) spaces between the leads of the surface mounted components and connectors. Allow the board to fully dry before re-applying power. Hope for the best; sometimes miracles do happen

.
edit: Q-tips and a dental pick (or toothpicks) can be used to clean out the spaces between the legs of the integrated circuits. I'll post a picture in a few minutes of what I had to do with a DIMM just last night.
I got this module from eBay last night and it appeared to have some thermal grease on one of the SDRAM chips. There was a small glop of it across three of the legs, so before I installed it in my Gateway desktop, I cleaned it off with alcohol and ran a dental pick between the pins of the IC. It
might have been non-conductive but I didn't want to take any chances with it.