Strange Partial Shutdown

[zootroye]

Hey All,
I just upgraded my mobo and cpu and i'm seeing some strange behavior.
The system runs fine, but once in a while, the system does a partial shutdown. The cpu fan and front fan will go dead. The monitor goes black, but the power is still on and the rear fan is running fine. I power down and resart and the rear fan turns on, but nothing else.
I unplug the cpu fan connector, plug it back in, start up, and everything runs fine.

Any ideas?
My voltage and heat looks good (CPU at 38C).

Help Please!
My wife will force me to buy Dell if this doesn't work.:frown:

 

[zootroye]

One more note:
The rear fan is connected to the power supply directly.
I think my MOBO is just shutting down.
What could cause this?

 

[Basie]

Are you using Motherboard Monitor to check your voltages and temps? If not you can get it here
http://mbm.livewiredev.com/
In changing your mobo and cpu did you do a reinstall of your OS?

 

[zootroye]

I checked my volts and temp using speedfan and the bios.
I did a clean install of XP.

 

[zootroye]

There is a difference in voltage described by my BIO vs. SpeedFan and MBM.

In the BIOS, I have a defined voltage of +1.5Vin which reads 1.441V. Looks good.
SpeedFan describes a +2.5V at the same reading.
MBM descibes it as CPU/IO.

All readings are at 1.44V.

Should it be 1.5V or 2.5V?