Strange happenings on a Samsung 42" Plasma

[CoogarXR]

A friend gave me a Samsung 42" Plasma, model PN42C450B1DXZA. He told me that his friend went to connect her laptop to the VGA port on the TV, and heard a BZZZT! sound, and the TV turned off. It was under warranty and it got replaced, so he didn't want the old TV (nor did Samsung or the service center, heh).

I thought the story sounded coincidental, like maybe something else happened at the same time, like a Ysus croaking of natural causes. But I finally got around to opening it up today, and sure enough, there is a big black burn coming out from under the VGA jack.

What do you think caused that? I don't know if the laptop was plugged in to the AC or running on battery, but my first thought is something like ground differential. What do you guys think?

The board is burned beyond repair (several SMD components cooked). The board is only like 10-15 bucks on ebay, so its no big deal. I just don't want this to happen again if somebody uses the VGA port.