Hi nasomi, this might've come up in the thread already.

It is definitely the gpu (gtx280). There's loads of bad cards out there that need to be replaced or scrapped, specifically the gtx280s.

Baking is a solution I am not comfortable with, but has resolved one person's issue.

As for me, I underclock my card to 620 just to use it without crashing, biding my time until a worthy successor is available for trade-n at MicroCenter (due to the cost, it's one of the few receipts and original boxes I keep track of.