Hey, all -- would appreciate any thoughts on this. Been using the same machine I built in college for about a decade now, with a GPU midlife upgrade but otherwise without any big changes or problems. While web-browsing two days ago, suddenly it wouldn't connect to USB and then seconds later unexpectedly powered off. Upon trying to restart, my Asus motherboard starting flashing a 00 code. Briefly, the monitors continued to work, but now they won't connect, either.

I did some googling and already tried clearing the CMOS by pulling out the battery, to no effect. Also tried getting into the bios by pressing the function keys (and delete) while restarting, and that hasn't worked. I can't figure how to get into the BIOS at all, and without the monitors working, I'm at a loss. I'm hoping there's something dumb I'm missing! Would be grateful for any help.

Here's a quick link of the internals -- my cable management is not great but looks worse than usual in this... https://imgur.com/a/9YE5NMS

I just finished connecting all the parts, click on the power button and nothing, code 00 stuck, i removed all ram sticks but 1, checked psu connectors, clicked on bios clear button. Nothing.

Asus dark hero z790 14900k Gskill trident z5 ddr5 6800 48gb

Hopefully some people here might've encountered and solved this problem, but essentially, while my computer is running, after around 36 hours (all the way to 72 hours) of uptime, I get a random motherboard error code of 00 and my entire computer becomes unresponsive with the display completely black.

My components are:

CPU: Ryzen 5950x

Motherboard: Asus Crosshair VIII Hero X570 (Wi-Fi)

Ram: 128GB Corsair Vengeance Pro RGB (4x32GB) 3200CL16

GPU: EVGA RTX3090 FTW3 Ultra

And an assortment of 3 HDDs, 1 SATA SSD and 2 NVMe drives.

I initially thought this might've been a PSU issue (my previous one was 800W and almost 10 years old) so I bought a Seasonic GX1000 to replace it and while it initially appeared that the problem had gone away, it started again after a few days of use.

It's not a temperature problem from what I can tell given that every measured temperature in the system is reasonable (CPU below 80C most of the time), one thing it could be is that the chipset has overheated as my GPU does block a portion of the chipset fan, but I've not seen this in the temperature readings - is there even a way to diagnose this?

I sent the parts back to the supplier (in the UK, suppliers do the RMA) and they tested the system and found no issues.

I've run memtest86 10 passes all passed (this takes more than 24 hours with my quantity of RAM), prime95 for more than 24 hours, thrown multiple 3dmark stress tests at the system and used it for gaming all without instability. But this issue randomly happens without an indication despite the system being under only mild load (and constant mild load). I've even run a stress test for 40 hours and had nothing happen.

I'm at my wits end here and I don't know what else to do. Would be very grateful if anyone has an ideas.