So, I have a HIS IceQ X 6770. It was working great for awhile, but recently the fan has been temperamental and only spins at certain times, and a lot of the time I have to start the fan with my finger for it to actually spin on it's own. It will work fine under regular use without the fan spinning, but if I do any gaming the card will stop working and the computer will shutdown. I've tried it in three different systems so far. In the first one it worked regularly without any problems except when you would play games. On the second system it would struggle to stay running just while browsing the internet. The third one it works fine when using it for the internet and such, but when you start to game the fan will kick in then stop and the card slowly gets hotter but it doesn't reboot. I'm lost at this point, because the results are different from computer to computer. Any ideas?
Are you testing this on different PSU? Maybe it's not getting enough power. Although it sounds more like something is just outright broken. You should probably send it back if it's still under warranty.
i would check to see if his has a bios update to fix this fan profile issue. depending on the cards bios and the ccc drivers it sounds like each system is setting there own fan profile. i would check using ccc pannel if there a fan speed or fan over ride. if not see if there a third party tools like msi afterburner for ati cards. if there not one or the card fan still wont speed up on heat ramp i would rma the card.