Firstly I bought this card second hand so doing an RMA isn't an option (it's about the only advice I've seen for similar issues.)
 
Everything seems to work but when I boot the PC only one fan spins up, and then it stops as it should. I know both fans should turn on once the card hits 60c but this card waits until it hits 70c then only one fan (the closest to the i/o ports) spins up at 100% and the other doesn't move. Once I exit any game and the temps drop back down the one fan stays at 100% and doesn't stop until I restart the computer. (It's pretty loud so leaving it running isn't ideal.)
 
When fans are at 0% Precision X shows 0. If I force even 2% on the fan speed the one stays still and the other goes to 100. When the fan is at 100 Precision will show the fan speed it's trying to control (showing 30-45% yet the fan is still going 100)
 
Steps I've already taken:
 
Removed and reinserted card
Removed and reconnected PCI-e cables
Removed fan shroud and check cable connections for fan headers (unplugged and reconnected fan headers)
uninstalled precision X and reinstalled making sure to NOT save previous profiles
uninstalled and reinstalled nvidia drivers
 
I've seen many posts on this issue so I know it's a known issue with these cards but all the posts are 3+ years old back when the cards were first released. Was wondering if anyone had come up with a fix in the years since?
 
Appreciate any help.

Yeah that was about the only idea I could come up with. Appreciate it.

I ran into what I think is the exact same problem on my EVGA 980 ACX 2.0.
 
One day out of the blue, one fan would not spin and the other was at 100%.  I removed and checked the fans with a 12v battery and one of them was dead.  Upon closer examination the PWM controller chip on the dead fan's PCB was damaged and burned up.
 
I bought a new pair of the same fans on Amazon (pair because they are wired to one connector).  Installed them, and it's back up and running good as new.  I didn't find anyone with the exact problem at the time so hopefully I can help someone else repair their 980.