PC won't start; fans spin for half a second then stop

[Nineshadow]

When I arrived home today I noticed that my desktop wouldn't start. The fans spin for just a moment, then stop. The process repeats itself until I turn off the PSU. I have to mention that I haven't touched the PC in a about a week, and that it was working fine the last time I used it.

I recorded a small video, for clarification

I started troubleshooting things. Checked RAM, fans and pretty much everything that you can easily check. None of them were to blame. Then I tested the PSU with the paperclip test. I connected the hard drive to the PSU and it was working. Again, here's a video:

Note that the PSU fan doesn't spin initially because the PSU is semi-fanless, the fan doesn't spin unless the PSU reaches a certain temperature. When it shuts off, I guess the fan spins a little bit to get rid of dust, I've heard of similar techniques used by other manufacturers.

 

So this leaves the motherboard as the most probable culprit. I even tried removing the motherboard from the case and running it outside, but alas, nothing happened. I suspect a power surge shorted something in the motherboard.

[Guest]

I think it is shorting somewhere in the MB or in the PSU.

[PLME888]

Clear the CMOS battery, that might help

[Nineshadow]

9 minutes ago, PLME888 said:

Clear the CMOS battery, that might help

Nope, just tried it.

[Nineshadow]

2 hours ago, OVD123 said:

I think it is shorting somewhere in the MB or in the PSU.

I'm trying to figure out where. My PSU is still covered by warranty so at least I can RMA it.

[Nineshadow]

Update: I've managed to get my hands on another PSU and it didn't work. I tried using another mobo and the system worked. So the mobo was definitely fried. Oh well, time to buy a new one I guess