Wonky System Startup Issue


Sep 23, 2005
I'm having issues during start-up of my latest PC build.

First thing: this PC works! Just having some weirdness on startup. Once started it does not have performance issues. I have been able to get it to start each day, after some trouble.

Here's the system in question:
  • ASUS TUF Z490 Gaming /w WIFI
  • Intel Core i9 10900K
  • Corsair Vengeance RGB Pro 64GB (4 x16GB) DDR4 3200
  • Intel 665p series M.2 2280 2TB NVMe SSD
  • eVGA GeForce RTX 2080 XC Black
  • Corsair HX1200i PSU
  • Corsair iCUE HT150i RGB PRO XT
  • Corsair Obsidian 750d case
  • Win 10 Pro
Temps & Performance:
Now here's the issue.

Each morning when I go to power on:
  • I push the power button and it does nothing,
  • I push the power button again and I can hear the CPU cooler pump start up, then the fans on the radiator engage and then throttle up and it will stay stuck like this. No activity on the motherboard, change in LEDs, no other signs the system is powered on.
  • If I push the power button again it does nothing. I have to either hold power for 5 seconds or flip the power switch on the PSU.
  • After a few attempts the behavior changes. It will get a little further and LEDs on various components will start to flicker and then it will power off.
  • After a few more power on attempts; it will finally power on, normally.
  • Whole process takes between 2 and 20 minutes. I have been able to get it to start every day, after some trouble.
  • The steps and behavior are a little different each day, but generally go like this.
Troubleshooting steps I've taken:
Finally, here's a video of the behavior:

If there is any other related info I can provide, please let me know. I'm at a loss here.
I can't believe I didn't think of this. My friend suggested a BIOS update. I have a vague memory during the setup of downloading the zip and seeing it was a *.cap file and putting it off until later because I didn't want to deal with it. LOL.

So I looked and I was on version 0321 which is six releases old.

I just flashed to the latest version 1410, released Oct 15, 2020.

I'll update this post tomorrow. Here's hoping this whole issue was just me being scatterbrained.

Still open to ideas, questions, suggestions.
Multiple friends have mentioned to me that it could be power related. I remember during the build that there were two CPU power plugs: an 8-pin and a 4-pin.

I didn't hook it up because the manual hinted and google suggested that the second one was for multi-GPU setups. My power supply came with two 8-pin CPU cords but they didn't split into 4-pin. OR SO I THOUGHT.

Turns out it totally does. I took a closer look and yeah, I can hook up this power connector and I'll do that tonight.

Between the BIOS flash and the discovery that I might not be fully powering the motherboard I'm hopeful a resolution is in sight.
Final update. None of the above troubleshooting led to a resolution.

It was the damn UPS I had it plugged into. Not sure what that's about. Why it would work but only after "warming it up".

I have it plugged into a simple surge protector now and it's been working fine.