Originally Posted by Volt-Schwibe

omg.

i think what you are seeing is stains from magic smoke.

look really close at what we've got here... this is my guess, keep in mind.

when these traces on the motherboard exceeded their load rating, they literally vaporized, and the smoke from the pure copper left that yellow stain in a downward pattern.

i suspect that's actually "upwards" while the machine is running...

can you rub it off with rubbing alcohol?

this could have been a shorted case mount, or something.

i'd carefully inspect the board to see if there's any "sparky" looking spots