I've had an Asus 4850 for about a year: great card for $85 but the fan on it died. It had a three year warranty and I sent it in after tracking down the right form (harder than you'd think). After ...

So I built out a new box some months ago with the help of the fine Ars folks and it's been running great until recently.. for some reason the fans seem to randomly ramp up high for a few seconds then ...