Why are you being aggresive. We are just offering advice on what to do/try.
As its also been subject to water damage, the fault could also be any where. I remember repairing a laptop, which had been submerged in water.
It was left to dry out completely, upon testing it, it would not post. No water was visable, person ended up scrapping it.
3 months later, stipped it down, for something to do, removed CPU and low and behold, there was water trapped in socket. Cleaned it up and it booted and worked perfectly.
This is just another example of what it could be, remember yours is not a common break down or cap leakage.
Maybe there is still some water ingress, may sound crazy, but in my example, after 3 months of being sat there, there was still water under CPU.
Your may have some ingress under one of the chips, who knows until its looked at.