New build, won't power up with ATX 12v connected

[Deerspook]

I'm building a PC for the first time. So far I have been unsuccessful getting it to post. I have the issue of nothing powering up when the ATX 12v is plugged into the motherboard. When it's plugged in, there is an audible click in the PSU and nothing happens. Unplugged everything powers but obviously no post or video. Here is what I have checked so far. Swapped with new extra mobo I have, same results. Jumped green and black on PSU, PSU powers up. Reset cmos, same result. Removed gpu and ram, same result. Removed mobo from case and duplicated tests, same results. To me this points to a short in the CPU causing the PSU to power down. But I would like a second opinion as this is my first build and I might be missing something.

Here are my specs:

Mobo: Asus m5a78l-m
PSU: rosewill photon 850w
Cpu: amd fx 4350
Gpu: sapphire Radeon r9 380
Ram: corsair 2x 4gb vengeance ddr3
Cooling: corsair H100i gtx liquid cooler.

Just need a second opinion, thanks.

 

[popatim]

sounds like you have a short somewhere. make sure you are not plugging in the pcie power cable into the cpu power plug (eps12/atx12). they are wired exactly opposite and will connect 12v directly to ground if you did do this.

 

[Deerspook]

sounds like you have a short somewhere. make sure you are not plugging in the pcie power cable into the cpu power plug (eps12/atx12). they are wired exactly opposite and will connect 12v directly to ground if you did do this.

Atx on the mobo is 4 pin and the psu ports are labeled as CPU/ PCI-e for what I have them plugged into, it also doesn't matter if any of the PCI-e cables are plugged into the gpu, same results either way.

 

[Deerspook]

Reading through my PSU manual it specifies the cpu cable as eps 12v, will this cause this issue or are the cables universal? The PSU itself is eps/atx compatible.

 

[helpstar]

It's compatible. Did you test the hardware outside a case? Use wooden surface, no esd foils or packaging under the motherboard.

Did you try plugging all power connectors into the motherboard+cpu+one ram?

Which Asus m5a78l-m
is it exactly? Maybe the bios version is to old for the FX cpu

Try another psu

 

[Deerspook]

UPDATE-

I was using corsair sleeved cables for the atx 12v power supply. I swapped it to the stock PSU cable with no gpu and I got post. Installed the gpu with sleeves cables, no post, put stock PSU cables on video card and bingo success...looks like no sleeves cables for me.

Thank you popatim for your response, you got me questioning my power cables and I was able to find the issue

 

[ko888]

Corsair modular cables on a Rosewill Photon PSU made by Sirfa. That's precisely where the problem lies.

PSU modular output cables are not universal.