Z790 Apex broken?

[yaa11]

So I just received my z790 apex and changed it for my MSI z790i Edge.

After 2 hours of hard work I press the boot button and my PSU clicks endlessly and the pc obviously doesn’t boot. Debug LED showing 00.

So without the gpu connected it goes to POST (probably, don’t have video to verify) and the debug LED starts working and the fans start spinning fast.

With gpu, same psu click.

But:

whenever I press “clear cmos button” I can boot for exactly one time. I can restart within windows and it will boot again. Only when I full shutdown, it won’t turn back on (and psu clicks) unless I clear cmos again…


I will try flashing bios now but I suspect there is something broken on the board as the exact same hardware (with the Mail z790) was working without issue.

*
4090
7800 gskill
13900k
Sfx 1000w thermaltake *

[yaa11]

Or could this also be the psu? Because now when I remember when I first ran my msi z790 I also had weird issues and had to start with 1 ram dimm only and do a bios update. Since then it’s working perfectly*

[yaa11]

Z790 apex bios update didn’t help btw. Same issue*

[JohnAb]

I've never had a PSU that clicks, doesn't sound right. Hard to say for sure, but worth swapping out I think if you can easily get access to another one. Have you checked that the PSU cables are properly seated? (on the PSU, motherboard and GPU).

[yaa11]

When you open the switch at the back of your psu, you can hear a “click” (many psus do it).

And this sound keeps repeating. Like it “can’t” power the board and keeps on trying over and over.

Cables are all seated perfectly etc. Should be no mistake on my end*

[JohnAb]

OK, well I'm not sure what the problem is, but my money would be on the PSU at this stage... could be something else, but the PSU is certainly cheaper and easier to swap out than the motherboard, so that would be my strategy (unless you can borrow a PSU for testing which would be best, obviously).

I'm also a little suspicious about the GPU, because you say it seems to POST when that's removed. Sorry that I don't have an answer, just a case of elimination I think.

[yaa11]

Like I said. System works perfectly fine on the z790 msi*

[JohnAb]

Ah, well maybe you got a bad motherboard then if that's the only change. But why would it POST without the GPU if it's the motherboard?

[Defgun]

Did you connect both 8 pin power connectors to the Apex? Because your MSI has only one 8 pin connector and maybe just maybe something is wrong with either the PSU or one power cable. But I don't actually know if this would even prevent the boot as I think the second 8 pin power supply is only needed when you go for heavy overclocks.

[pndiode]

Ensure you do not have an extra motherboard standoff screw when you install the z790 Apex. The Z790 Apex has 9 standoff screws. The Z790I Edge only has 4 standoff screws.

PSU clicks endlessly and the pc does not boot. PSU overload protection circuit is working (3V, 5V, or 12V being shorted to ground).

No GPU connected, not much weight on standoff screw and motherboard POSTs. The fans start spinning fast (12v shorted to ground).

Just a guess there might be an extra motherboard standoff screw. I could be wrong.