2 months after owning this card the fan stopped working i never sent it to be repaired because i wasnt happy with the cooling ,it hit 75 to 80 degrees on full load. so i brought a Accelero Twin Turbo silent cooling upgrade and after the upgrade full load was silent and reached 55 degrees i was happy for several months until today after playing crysis i noticed the temps hit 60 degrees so looking inside the pc case only one gpu fan out of 2 was working even though the fans for the gpu are connected directly to the psu via a molex connector i took the card out of the pc for a closer look couldn't see any damage to the other fan and thought 60 degrees on full load with only 1 fan working is cooler than the stock cooler so put the card back in and turned the pc on but now in the BIOS i get lots of multi colored lines and flickering squares something is seriously wrong which gets alot worse and unusable if windows loads i really don't know what is wrong with the card or how to fix it im thinking of doing a bios gpu update if possible in this state at the moment ive downgraded to a Radeon HD 2400 pro which is to be honest its rubbish also i reapplied the thermal paste and that has not fixed it
Raidmax Ninja Case
Oryexx Hercules 750w Crossfire Ready PSU
AMD Phenom X4 9950BE QuadCore CPU
ECS 7050 M-M Limited Edition Motherboard
2x 2GB Corsair XMS2 DDR2800
Samsung 500GB HDD
Bluetooth wifi 2 in 1 card
Optiarc/Sony dvd all multi lightscribe RW
ATI Radeon HD 4870 512MB
In all honest truth I would slap the stock cooler back on and contact ASUS for a return. The temps with the stock cooler are more than fine. I had the ASUS dark Knight 4870 and during Crysis it always hit around 80-85C and never had any issues at all.
Returning it should fix the fan and let them know you were experiencing the artifact items on your screen.
You will want to resell the card someday and that day you will want it to work properly. Trust me I've tried to get around warranty repairs, but a GPU is just that one thing that its usualy best to send back. Motherboards are right there along with them. They are a pain to remove and send back, but in the end you will be happy you have a totally functional unit.