Mainboard fault

[golumolu]

I am using MB with Intel 845 chipset,350watt smps,512mB RAM...
My machine is not starting and CPU fan stops just after starting for 3-4 sec..I am sure that the CPU,RAM and SMPS are OK.I think the problem is in the MB.What is the probable cause ? Kindly help me to solve the problem.....

 

[natto fire]

Are you sure it is the power supply? Do the rest of the fans stay running? Have you tried resetting CMOS, reseating hardware, or are you getting any error beeps?

 

[golumolu]

 

[golumolu]

SMPS is OK.
CPU + CPU are OK
RAM ok
After pressing the power switch CPU fan starts for 2-3 sec.
But then stops.
Cabinet cooler fan is running.