Dell Optiplex mobo swap not working

[tragicallyhip]

I put a 3.2GHz prescott cpu into a mobo that formerly held a 2.8GHz cpu and installed.
:no activity except for mobo led and front panel led went on, everything else was dead.
I repeated this same swap once more with a different 2.8GHz mobo with the same results.
I went back and re installed my original 3.2GHz and mobo and everything is perfect.
I went for 3rd try only this time dropped a 2.8GHz cpu/mobo straight into the case without touching anything and results were same as my first to installs,nothing except the mobo's green LED is on as well as the front panel on light.
I changed out psu's using the original functioning one and an after market unit with no change in result's.I also double checked all connections during each swap.
Is there some mystery force that keeps any other cpu/mobo from working in this case?
The World Wonder's
Help me
thx
Tragic

 

[Ididmyc600]

Hi

im sure someone once told me that Dell use propriatary PSU's, that is to say they dont use standard PSU's in their machines.

 

[mailpup]

I'd say the processor is not supported by that motherboard. Even though it physically fits there have been so many different models of socket 775 processors, they are not all compatible with all socket 775 motherboards. You could try updating the BIOS of the motherboard in question although you might have to use the original processor that came with it, if available, but there's no guarantee it will work.