CPU Won't Start

[Ariharan]

Hi, This is Ariharan.
This is my First post in my life,

My CPU Config G31 motherboard,C2D, 2Gb DDR2 Ram.

Problem was when I power on my CPU. Processor fan and SMPS rotate for only 1 complete rotation(Jerk type) after that it goes to OFF condition after that I try to start again it won't ON. I unplug the power cable from SMPS and plug it again and press the power button again. Its same only, Processor fan and SMPS jerking.
I checked below mentioned,
1. CMOS Cleared and battery changed
2. RAM changed
3. SMPS changed
4. I don't use Graphics card. I am using VGA onboard.
5. Every thing I unplug and plug it again.
6. I connect only Onboard VGA then for start I use to Shot the power pin. That's all

In my problem CPU RAM,SMPS I checked with my friend's computer it working fine only.
I don't know what was the problem in my CPU..

Please Help

 

[Cycloid Torus]

I think you are saying that the CPU, RAM and PSU (a/k/a SMPS) have all been checked on a friend's computer and they are operating properly. Did you confirm proper operation of CPU fan, mouse, keyboard? Did you try to operate your system with storage, DVD and other accessories removed?

If you have done all that, I would think it was the motherboard and I would closely inspect that under strong light and magnification for brown spots and swollen capacitors.