Motherboard Problem ???

[PL_Kuba]

Hey pc experts!

My friend gave me a dead system to help him fix it. He told me that he smelled burning and it doesnt turn on at all. After I pluged in the power cord to psu and turned it on I noticed that the fan in psu doesn't spin and psu makes only a continues strange noise. I replaced the psu with the good one thinking it's the obvious problem but the problem is still the same. I suspect that it's the mobo that gone bad. What do you think? How should I troubleshoot it to make sure it's the mobo that is not operational?
Any advice is helpful. Please help! tx in advance

[xiankai]

u did the right thing...

its either your mobo or cpu... cpu often get fried more than mobos, so thats my bet. but the fans shld still spin :/

check out the cpu to see if it has any characteristic damage.

[Panama Red]

How old is this system? If the mobo is one that uses the ICH5 Intel Southbridge, it may be that chip that has burned. It is used on many manufacturer's P4 mobo's using the 865 and 875 Chipsets. We've had quite a discussion here about these failures. I've seen two myself. Just a possibility to consider.