phoenix miner just stops on two 6990s, but one core still runs?

[clonedone]

hey I have 11.5 cata
2 6990s crossfired
and phoenix 1.48

for some reason every couple of hours, the 3 of the 4 gpus just stop running and only one still runs at 333 m/hash
the other three look frozen, but the computer is not frozen.

its very cool in my basement, and i checked all the power cables again. anyone know whats happening?

I have another setup with also two 6990s. everything is same except the brand of the video cards but that shouldnt matter right?
my other setup works beautifully.

[travex]

PSU power ?

[clonedone]

ahh sorry 1250 watts, same as my other setup

[Basiley]

"stop running" HOW ? with burn and smokes ? completely no output and fans stop ? just miner stop ? or "everything seems okays, except miners not start" ?
waht in windows/linux[whatever you use]logs about such even[there SHOULD be even 4 this].