Computer suddenly sparked and stopped booting; CPU fan power cycles; what could be wrong?

[stanleywinford]

At work, I have an old computer with an Intel DQ45cb motherboard, 8 GB of RAM, a Core 2 Quad CPU, and Corsair CX550M power supply. Today, I was working at my computer when it suddenly went black. There was a spark, then a strange smell. The computer then refused to boot. After connecting the motherboard to power, the CPU fan spins up for about a second before spinning down again, the RAM LEDs are lit (as they should be), and the "AMT LED" flashes at the same rate as the CPU fan power cycle. The keyboard, mouse, and display don't respond, and there are no beeps.

I tried:

1. Taking the motherboard out of the case, and disconnecting all cables except the power
2. Using only 1 stick of RAM
3. Disconnecting and reconnecting the main & CPU power connectors
4. Reseating the CPU
5. Using another power supply
6. Taking out the CMOS battery
7. Clearing CMOS with a jumper
8. Clearing out the dust

Should I just assume that the motherboard/CPU/memory is dead? What could have caused it to die like that? Also, which component (motherboard, CPU, or memory) is most likely to be the problem?

 

[jwcrellin]

Power surge probably fried your components. Sorry mate.

 

[stanleywinford]

Power surge probably fried your components. Sorry mate.

I was thinking of using the same PSU (Corsair CX550M) for different components. Do you think that's safe, considering that the PSU couldn't deal with the power surge? Also, why would a power surge destroy my computer but not the other computers in the same room?