[MSI K8N Neo2 Platinum] Is the motherboard dead? HOW? What? Hein?

Question

Hey!
I am having big problems with my MSI K8N Neo2 54G Platinum. It was a really great board until the day the system could not power up. I pressed the button to turn it on and nothing happened. So I shutdown the switch of the PSU and switch it on again, while looking inside the case. This time the CPU and Northbridge fan moved, and the led of the wireless card turned on. But that happens only for half a second. The fans imediatly shut down. I checked if it was the problem of the case button, but it is not 'cause with a direct connection the same happens: the board won't boot. It doesn't even beep. Completely quiet. Any suggestions? 
I am sorry for my English and thanks in advance
A64 3000+ 90nm s939
MSI K8N Neo2 54G Platinum
2x512 Patriot XBLK TCCD
200GB Sata
20A@12v PSU
PS: The computer was working fine 'till this happened.
Nukke.

Answer 1

Yes it can still be the PSU , e.g not accepting ps_on giving pwr_ok to mobo in-line with the correct timing specs .
It can also be motherboard not sensing pwr_ok from the psu .
The whole startup proceedure of a modern PC is complex and it is more to it than just amps and wattage and a on/off switch.
PSU itself does Power On Self Tests (POST) before the motherboard starts to powerup.
These tests determine if all the voltages are up to design specification and stable before sending a signal to the motherboard.
If the POST completes successfully, a POWER_GOOD or POWER_OK signal is sent to the processor over the POWER_GOOD line.
This signal must be continuously present for the system to operate and, if withdrawn (due to a brownout, for instance), will generate a system RESET.
The system will remain in a continuous RESET mode until the signal is restored. Since the processor initializes in the RESET mode, the system will not start until sensing the PWR_OK signal.
The AMD64 systems is strict to the power up sequence and at startup of a non mobile system
like this desktop motherboard the power state registers in the cpu is to be set/started correctly , and they are initialized with full power.
This aswell as the motherboard and PSUs cooperation of the ps_on/pwr_ok sequence and timing is in-line with
the latest atx spec makes it hard to say exactly where the problem is when things like this happends.
This is one of the major reasons we who replies here recommends "known" PSU brands , not only 12v=30A , cause
that "high enough" amperage don't mean s**it if the PSU is dodgy when it comes to theese other factors.
It's all quite complex , all that needs to be in-line and within given times and values that happens in the system when you hit the PCs on-button .
It involves sequences , initiations and values done by/in : CPU / p-states /LDT / Memory controller / motherboard / PSU  , and more.
So an investment in a "good" ( known brand , respectable manufacturer, well reputated and with enough amperage ) PSU is a solid investment
that will serve you well for a long time , not only in current rig but down the road also .
Down the road if you also add some reserve for future updates when it comes to the strenght of power on it rails , then you may have goin_on it in several builds and updates.