Question Newly built PC only boots up if Cmos was cleared beforehand

[UnboxedMichi]

My newly built PC has one major Problem: It only succesfully boots up and enters the BIOS menu if I cleared Cmos beforehand. Otherwise it gets stuck during the booting process.

My main Components:
Motherboard: ASRock Riptide Wifi Intel Z890
CPU: Intel Core Ultra 5 245k
GPU: RTX 3060 ti
RAM: 2x 16GB DDR5 (Kingston Fury Beast EXPO DDR5-5600 DIMM CL36)
PSU: Corsair RM850x (850W)
boot device: 2TB SSD in M2.1 Slot (2TB WD Black SN850X)

Every component except the GPU has been purchased new.

Detailed description of the issue:

I've assembled the components together and into a case. I have not installed any operating system yet. There are two different scenarios which happen depending on whether I clear Cmos before powering on the PC or not. I've reset Cmos by connecting both CLRMOS1 pins with a screwdriver for 10 seconds. I did not take out the Cmos battery at any point, since I did not know how to do so.

1. Powering on the PC without clearing Cmos beforehand: After plugging in the PSU and turning it on, the RGB-Lights on the motherboard and GPU start lighting up. After pressing down the power button on my case, the cpu cooler and case fans start spinning. My ASUS Motherboard has 4 debug LEDS. The red LED which indicates a CPU Problem goes out quite fast. After some time the orange LED, which would indicate a DRAM issue goes out too. Now the white LED, which indicates a VGA issue turns on and stays on permanently. The green LED, which would indicate a 'boot' issue stays on permanently too. My monitor, which I connected via an HDMI cable to my Motherboard tells me it receives "no signal".

2. Powering on the PC after clearing Cmos: After plugging in the PSU and turning it on, the RGB-Lights on the motherboard and GPU start lighting up. After pressing down the power button on my case, the cpu cooler and case fans start spinning. All 4 of the debug LEDS go out after some time and I am able to enter the BIOS menu, which is displayed on my monitor, which I connected via an HDMI cable from my motherboard. In the BIOS menu all components (CPU, RAM, CPU cooler fan, the case fans) appear successfully and seem to work without any issue.
If I now power off my PC and power it on again, I am not able to enter into the BIOS menu and am again stuck on the white and green debug LEDS, which stay on permanently. My monitor receives "no signal".
If I clear Cmos again and power on the PC it works fine just like I described earlier and I am again able to enter into the BIOS menu.

Things I've tried already:
- I've tried testing the build with and without the dedicated GPU (RTX 3060 ti). The results were the same whether I had an dedicated GPU plugged in or not.
- I've updated the BIOS of my Motherboard to a newer Version (2.16). The issue persisted
- I've tried taking out the SSD and Ram sticks and putting them back in.
-I've checked for loose cables on the PSU and on the Motherboard.


This is my first time building a PC so I'm not really sure what to do next and whether I should install an operating system anyways or not. My guess would be that the issue doesn't lie with the components, since all of them have been successfully listed in the BIOS. The Motherboard is also quite new, which is why I find it hard to believe that the issue lies within it.

Any help or advice is appreciated

 

[Ralston18]

This motherboard?

https://download.asrock.com/Manual/Z890 Riptide WiFi.pdf

Be sure to verify that I found the applicable User Manual.

Re-read/review the full User Manual along with the documentation for all installed components.

Carefully check all plugs and connections to ensure that they are correctly, fully, and firmly in place. Especially case connections.

Pay attention to all fine prints, warnings, notes, etc..

For example: See the "DO NOT" remove note on physically numbered Page 14. It would also be natural for people to remove the shield if they had not read the User Manual and believed the shield was just "packing/shipping" material....

Go page by page, check things off, make notes.

Take your time. If something is amiss then correct if possible. Otherwise, stop and focus on resolving the problem before proceding.

Hopefully just some error of omission or commission.

 

[UnboxedMichi]

This motherboard?

https://download.asrock.com/Manual/Z890 Riptide WiFi.pdf

Be sure to verify that I found the applicable User Manual.

Re-read/review the full User Manual along with the documentation for all installed components.

Carefully check all plugs and connections to ensure that they are correctly, fully, and firmly in place. Especially case connections.

Pay attention to all fine prints, warnings, notes, etc..

For example: See the "DO NOT" remove note on physically numbered Page 14. It would also be natural for people to remove the shield if they had not read the User Manual and believed the shield was just "packing/shipping" material....

Go page by page, check things off, make notes.

Take your time. If something is amiss then correct if possible. Otherwise, stop and focus on resolving the problem before proceding.

Hopefully just some error of omission or commission.

Yes, that would be the correct User Manual for my motherboard.
I've taken my time and went through each cable and component step by step along with the manual and they're all plugged in tightly. All PSU-Cables are locked into the PSU and into the Motherboard and GPU. I've also checked all of the cables, which came together with my case.
I also did not take off the Memory OC shield (page 14 on the User Manual).
The only aspect that could be amiss is that I've only been able to install 9 standoffs instead of 10. My motherboard shows 10 holes, in which standoffs would fit, but my case only had 9 standoffs installed. Since I did not know how to add another one, I installed my motherboard into the case with only 9 standoffs. Is this really something that could cause this issue?

The thing is that everything works fine, the PC will boot and I am able to enter into the BIOS if I cleared Cmos beforehand, which is also why I created this thread. This seemed really weird to me, since everything seemed to work fine (if I cleared Cmos before powering on). Is there something else I could be missing that causes this weird behaviour?