I had a DFI LAN Party NF4 that literally blew a component off while in use. I heard a pop, went and looked at it but it was running fine so I never thought twice about it. Sold it on Ebay 6 months later and had the buyer freak out on me.
He found where the board had popped and subsequently left a burned trace, and demanded his money back. I looked at the pics I had posted for the sale and saw enough to justify the return. I assured him the board was functional (it ran fine 6 months after the initial pop !!) but he wasn't chancing it, and acted like I was trying to scam him from the start. I even asked to have it shipped back to me at my cost, but he wasn't even going to do that for me. I don't sell on Ebay any more after that.
I had another 939 board die on me, a Foxconn P.O.S. bought from Geeks.com, but seeing as how I probably had my hands on 100 boards over the years, 2 out of 100 is damn good odds.