I have an open rig of 6 ASUS GTX1070's running strong since july 2017. No problems with performance differences between the cards, each one running 30 mh/s ethereum at 48 degrees celcius. However, the card on the right outer side has some kind of dark colored spots on the pcb? It looks like grease, but its on the pcb solid, can't get it off. The other cards don't have this. Any ideas?
Normal card:
And the one with the dark color spots: