Asus radeon hd 3850 fan not spinning

Well you have a dead fan for sure. You may also have a dead video card.

Gee thanks, anyway off to by new GPU then  

Do you have the ability to put another fan on your video card to test it? Can you try using onboard video and see if it works?

The motherboard doesn't have onboard video, and no i can't put another fan on, maybe i'll take it to service and try to repair it.

It's probably more cost effective to purchase a new gpu if you don't have the ability to repair it yourself.

Yeah, nice way to start new year  
Get a new GPU

If you had been entirely satisfied with its performance, a HD6570 would offer similar performance, or perhaps slightly stronger if it has GDDR5. Let us know if you'd like suggestions on what to get if you'd like an upgrade; we'll need to know your monitor resolution, PSU brand and model (not just wattage), and the games you want to play.