voltage stuck on 5970

[cuz0882]

I have 3x 5970's in one pc, and I can't get the voltage to go up on one core. I have tried swapping out the card with another one and I get similar problems. If I run everything on cg miner I get both cores on the card coming up as dead or sick. I'm assuming its because it tries to raise the mhz over the limit while the voltage is stuck. I only have the video drivers installed and have tried raising the voltage in afterburner but the option is not even there for that gpu. I have two other pc's with 3x 5970's and I don't have this problem. Any ideas would be appreciated.

[jake262144]

Find max stable overclock at stock voltage and stick to it.
Overvolting will hurt your power efficiency as the power usage rises by core voltage squared.

[cuz0882]

Find max stable overclock at stock voltage and stick to it.
Overvolting will hurt your power efficiency as the power usage rises by core voltage squared.

Power costs don't matter that much, its only 6% of profit atm. Also as I have worked on the problem some more, it seems I can't even raise the core from 725 or change it at all. If I change the voltage in afterburner I can see my hash rate start to rise but a split second later it drops back down to stock settings.