so PSU,CPU,DDR2,etc..all is OK stf later писал(-а): but the problem

so PSU,CPU,DDR2,etc..all is OK
stf later писал(-а):
but the problem was the PSU

yes, with the P5b-VM the PC turned on and I worked quietly all day ... then, today, it started to show signs of instability, this suggested to me that maybe the power supply wasn't too good.
same identical cards, memory, processor etc ... only different motherboard.
with the P5B-VM DO it doesn't even turned on, it doesn't started, giving the impression the problem was the matherboard.
instead it was the failed PSU power supply which however allowed the P5B-VM to start up, while instead it did not start the P5B-VM DO, giving the impression that the latter was broken.
Instead they have different power ON circuits who deceived me.
//--------------------------------------------------

about the XEON -
in fact, the P5B-VM DO does not support the
Core 2 Quad Q9650 (rev.E0.3.00GHz, 1333FSB, L2: 12MB)
the P5B-VM yes ...

Xeon® E5450 (12 MB cache, 3.00 GHz, 1333 MHz FSB)

olso for the P5B-VM bios need to be modified ?

Thanks!