Hello,

if you had to replace the mb AND the cpu because both were damaged, and the replacement parts (guaranteed being in working order? ) do not work like you say, maybe would be better to replace the psu , since it may be the reason the mb and cpu got damaged

@mazzinia_​ Thanks for getting back to me, I tested the system with 2 separate PSU's both are is working condition.

In this case maybe the motherboard is suffering from a short caused while installing it ?

I still think is strange that the original mb & cpu both failed at the same time... did something happed around that time, that you know of ?

At this point you could also try different cables from the power distribution board to the mb / cpu, or even a new distribution board 

@mazzinia_​ There was a heating issue with the first motherboard and cpu. When i took the chip out of the socket, the solder that held the transistors/capacitors in the chip socket had actually moved out of place. The solder had melted because of the heat produced. 

I will try it with a modular power supply rather than the stock power supply. If i have no luck over the next few days, i will be sure to let you know.

Aftermarket PSU's often boast more total power, but skimp on the 3.3v/5v rails.  Make sure the new PSU has at least 150w on those rails, or at least as much as the original PSU.  GPU cards also borrow from those rails(s).

I helped another user whose XPS wouldn't start with an aftermarket PSU, and it turned out to be the power issue on the 3.3v/5v rails.

This is unless only 12v rails are coming out of the PSU.

I don't think that the pinout of the psu/mb is standard to allow to just use a modular psu without rearranging the cables.

This said, the heath issue mentioned is not exactly normal and can be caused by psu/rail issues and cooling issues. What's concerning is that there are safeties that should power down the system...

I momentarily forgot about most Precision's don't take standard ATX PSU's.  There aren't any cables coming out of a 5820 PSU.  I take it it plugs into a power distribution board.  Dell OEM PSU is still the best bet.