MOBO or CPU dead?

[SteWoo]

Hey guys, I posted this thread a few days ago after I thought my PSU had blown. Basic jist of the situation was I was getting a few system freeze ups recently, mainly when playing games or watching videos. After a few hours or so my screen would just freeze, PC was still on along with all my peripherals but no key combinations would get me out of the frozen screen meaning I had to hold down the power button to turn the system off and restart it. After trying to diagnose the situation using MemTest86 and Prime95 I finally ran Furmark, and when I came back everything was off. I think my PSU had blown so I bought a new one which arrived last night, however to my horror after plugging everything in and pressing the power button not much happened. Components look like they are starting up (fans start spinning) but die after about a second, so I removed every none essential component and just have the MOBO and CPU power cables plugged into the MOBO.

When I plug the power into the PSU, flick the switch on at the back, then immediately press the power button on my case the PSU and the CPU fans start and die after about 1 second; I then have to flick the switch on the back of the PSU on and off to attempt to start the rig again. However if I plug the power into the PSU, flick the switch on, then wait about 5 seconds before pressing the power button on my case nothing happens. What could cause the difference of being able to at least attempt to turn on straight away as opposed to nothing happening after a few seconds?

The golden question also is which component could be broke, my MOBO or CPU? I have limited knowledge of components roles and responsibilities during something like start up so I'm kind of guessing at what is happening. I have attempted a few things to get my rig started up again:

Tried so far:

• Removed every none essential component; only CPU and RAM in MOBO with 24pin + 4pin cables plugged into board
• Cleared CMOS by shorting the 2 CMOS pins

System Specs:
CPU: AMD Phenom II X6 1090T Black Edition 3.20GHz (OC to 3.45GHz)
GPU: Sapphire Radeon R9 290 Tri-X OC 4096MB
Motherboard: Gigabyte GA-890GPA-UD3H AMD 890GX
RAM: Corsair XMS3 6GB (3x2GB) DDR3 PC3-12800C9 1600MHz
PSU: SuperFlower Golden Green HX 750W "80 Plus Gold" Semi-Modular
HDD: Western Digital Caviar Green 1TB SATA 6Gb/s
SSD: Can't remember exact SSD as I'm at work but I think it's OCZ Vector 150 120GB
Disk Drive: Samsung SH-118BB/BEBE SATA 18x DVD-ROM
Fans: 7 case fans

I have a friend who is willing to swap out a few components in his rig in a few days to see what component the culprit is but any advice and a bit of education on what might have gone wrong would be really helpful!

 

[pastymuncher]

This is what happens when you use crappy CIT psu's with power hungry components. I would guess that it's taken the motherboard with it. Not much else you can try until your mate comes round but that's the first thing I would swap out.

 

[Karateyid]

Is the rig plugged into an extension cable or surge protector? If so try changing it or connected directly to the wall.

Have you tried the paperclip trick with the psu to see if it's the psu only dead.

 

[pastymuncher]

The psu is new. The original was a CIT unit that blew up.

 

[Little*Freak]

Remove motherboard and check for damage and/or blown transistors in a well lit room using a magnifying glass. Get a good detailed picture of your motherboard and compare components/parts.

Might be able to confirm that it is the board that way, can suggest nothing else helpful, sorry.