How do you switch from low/high-power modes? Is it a hidden configuration setting or do I have to jumper something?

I'm running the blades off a backplane that's being fed by one of those HP DPS800's that the plane is designed to work with.

Out of the whole plane, I just have one "x" chip out of the whole setup. It "might" be a power issue, but I'm more inclined to think it's just a funky chip. I'll happily troubleshoot anything though.

EDIT: These are the non-overclockable blades. Does that mean there is no such thing as low/high-power mode?