The green hazy substance around the chips in the center area of your picture really looks like corrosion damage from a liquid spill.
Or, the very center has a large mass of melted solder, which could mean overheating, or, again, damage caused as a result of trying to boot up when there has already been damage, again,probably caused by a liquid spill.
Yeah, I come back to that a lot, because of what it looks like - and the common damage that I see resulting from a variety of different substances.
Your choice for the fix?
Get the logic board replaced.
I don't think that anyone can repair that damage in the center of your picture.
Because of that, your choice is purchasing a replacement logic board.