Question GPU defect, or problems with the PSU or MOBO? Literal hole burning through GPU

[xWinterSolstice]

I agreed to help fix my friend's computer. He said when he powers the machine on, he sees smoke and smells burning. and it doesn't boot into Windows. I did the same, and there was indeed smoke coming from the case. I examined it and found a burned/melted spot on the GPU. I tested a good GPU in the machine, and it booted into Windows fine. I want to tell him replacing the GPU will fix his problem, but I'm worried the damage to the GPU could have been caused by another underlying issue with the PSU or the board. Like I said though, everything works fine with a good GPU installed. Is it possible that a problem with the board or PSU would cause damage to the replacement GPU, or was the initial problem most likely a GPU defect or fluke? It's worth mentioning he has pets and the machine was pretty dirty with cat hair on components and clogging fans. Could the pet hair have caused a short-circuit or a hot-spot?

GPU (damaged): Geforce GTX 1060 6GB
GPU (good, tested): Geforce GTX 980 4GB
CPU: Intel i5 8400
RAM: 12GB DDR4
OS: Windows 10 Home
Board: unknown
PSU: unknown

 

[rgd1101]

ask for the brand and model of the psu