I've got a whitebox server running CentOS 5.7. It's a Dual Xeon 5620, 24GB of RAM. The mainboard is a SuperMicro X8DT6-F and the chassis is a SC825TQ-R720LPB. Dual 720W Power supplies.

We had a big power outage a couple weeks back that took down everything, I don't have any pre-power outage figures for this server, and the only reason I noticed these is because when I was bringing up the servers I was checking them out with more scrutiny than usual.

http://i.imgur.com/rSjiw.png (Image of voltage readings)

As you can see, CPU1 DIMM is low, +3.3V is high, 3.3VSB is high, +5v is high, +12v is REAL LOW (out of normal 5% (plus/minus))... and VBAT is off the charts.

With my whitebox VAR we've tried the following:

1. Swap out PSU with another server I have with the same PSUs.
2. Try different power cord
3. Update BMC/IPMI firmware in case readings were wrong (They aren't)
4. Update BIOS
5. Try different PDU
6. Try a different outlet and/or circuit
7. Replaced Voltage Regulator Unit

At this point, the only thing we haven't done, seemingly is replace the mainboard.. which is what the next step will be unless something else shines some light on the situation.

I should mention the system is rock solid otherwise which is a surprise given the 12v voltage is that far off.