PC turns on for a few seconds and turns off repeatedly

[IvanMuse007]

I found a MOBO with i3 540 that had a few bent pins and one that fell off (it's VSS and it's a ground pin so it could work with out it)
It also has one semiconductor "burned" and it wasn't booting
I have bent the pins back and it booted but only for a few seconds until it shut off and does that in a cycle
I will replace the semiconductor and see if it makes a change but I wanted to know could it boot without the semiconductor or it is causing the problem
Here's a video that shows the semiconductor and my attempt to boot the PC normally
https://youtu.be/nRY-ipzSOd4

 

[InvalidError]

I seriously doubt you will manage to get the CPU to boot with a busted VRM MOSFET: missing a whole VRM phase will introduce tons of ripple in the CPU's core voltage supply and increase the load on the surviving phases.

If the buck FET failed short, the CPU got zapped with 12V and is dead.

 

[IvanMuse007]

I don't really care if it died but I just wanted to use this parts as a spare
But I think this is the semiconductor I have to replace
http://www.digikey.com/product-detail/en/on-semiconductor/NTD4963NT4G/NTD4963NT4GOSCT-ND/2409628