New Build - Mobo Switches on and off instantly

sAlex666

Honorable
May 6, 2013
3
0
10,510
Motherboard: DX58SO http://downloadmirror.intel.com/18128/eng/DX58SO_ProductGuide02_English.pdf

Processor: i7 930

PSU: 400W noname (works as a charm)

I came across quite a few threads like this but I couldn't find my solution in neither so I post here in hope of a better answer.

When I turn on the PSU the LEDs flash, the fans spin but only for a fraction of a second and then it turns off and I can't do anything, unless I unplug the PSU and try again - to no avail. Also note that after this happens, the standby LED stays on but everything else is pretty much dead, pushing the power button (even the one on the MoBo) repeatedly will result in nothing.

I've resorted to breadboarding, I've taken the MoBo out, disconnected it from everything except the PSU (MoBO and PSU are connected with 2 cables through the main power connector 2x12 and 12v 4pin connector) and I only have a processor with heatsink installed inside it.
I've changed the PSU to a 600W one, and the result was the same.
I even tried starting it without a processor which didn't help as it didn't wan't to start although the standby LED was on, so after that I pretty much ran out of ideas.

MoBo is basically new, taken from the box, so I kinda doubt that it's broken, but I can't really find any other explanations?

I am a beginner with building from scratch, so am I maybe missing something here?

 
it sounds like you may have a ground somewhere. When you pulled out of the case same problem? Did you run it outside of the case? I had the same prob with my first build where a wire was causing a bridge between two capacitors.
 
A ground?
I did took it out, put the MoBo on a piece of cardboard, clear of all the other wires and connectors but it still won't start.
 
check your motherboard manual and check that the power switch cable from the case is hooked up correctly and that the polarities aren't reversed. Do you have a post beep when you start up? If not i would rma the processor.