Maximus z790 dark hero won’t boot

[Srtguy648]

Hey all so I just finished a fresh build and my computer won’t boot.

Maximus z790 dark hero motherboard, intel i9 12900k, 32gb of g skill rgb ram (2 16gb), nzxt kraken AIO, rog 4080 super gpu, LIAN li tl 120 fans, ROG strix 1000w psu.

When I hit the power on my tower the gpu and counter at the top flash on then off and they stay off. None of the fans and the aio turn on. The rgb on the ram turns on and stays on. I have no display on my monitor with gpu or bios hdmi port. Keyboard and mouse also have no power from motherboard

[inge70]

Then there is something wrong with the power supply or there is a wiring error somewhere.

Are all the spacers under the mainboard correctly positioned and is there not one too many under the mainboard?

Check the power wiring etc. again carefully.

[Silent_Scone]

Hi @Srtguy648 

As suggested by Inge70

Check the ESP12V and ATX 24 pin connectors are fully inserted.

If using extension or custom cables, revert to the OEM cables and retest.

Ensure the motherboard is correctly installed using the supplied stand-offs.

If no change test outside of the chassis.

[Srtguy648]

Hey @Silent_Scone so the motherboard did not come with standoffs. the 24 and 8 pin cables to the board are both fully seated and are cables that came with power supply. I will pull the board back off tonight and make sure I don’t have an extra stand off under the board. 
Also thanks @inge70 I’m pulling the board back up tonight and checking.

[Srtguy648]

Ok removed everything from the case and set it up with nothing but the ram sdd and gpu attached. I still have nothing.

 

 

[inge70]

I wouldn't test a CPU like that without a cooler. Unless you want to grill it.
You should also follow @dennys2009's advice and connect the cables correctly.

[Srtguy648]

Ok so update I now got the led at the top with the codes now runs for a few seconds and then it shuts down. I got the board to post 2 time hooked into the bios port on the mobo but for the most part it crashes.

[JohnAb]

Difficult to be sure, but I suspect that you have a faulty PSU (or possibly a defective motherboard) but my money is on the PSU. Get a PSU tester from Amazon, they aren't expensive, maybe $12-15. Good luck. 

Just noticed that you have no cooler in the images. If you have tried running it like that, the CPU will overheat very fast. Could that be your problem? Maybe you haven't, but thought I should mention it. 

[Srtguy648]

@JohnAb I have a extra 850 power supply that I was just using before I changed the mobo and it does the same thing

[dennys2009]

Check the connection of the CPU power connectors.
I think you have a mistake here.
A Pcie_8Pin_PWR is connected next to the 24-pin connector to increase power to devices connected via USB-typeC.