TUF Gaming X670E-PLUS WIFI - White LED after 9800x3d upgrade

[startlife]

The core components of my PC are:

Motherboard: ASUS X670E PLUS WIFI

GPU: ASUS GEFORCE RTX 4090

RAM: G.SKILL RIPJAWS S5 DDR5 64 GB 6000 MHZ CL30

PSU: SeaSonic Prime GX-1000

The build is 2,5 years old and has been running without issues this whole time. Recently I upgraded the CPU from Ryzen 9 7950x3d to Ryzen 7 9800x3d. Ever since I assembled the components the PC has been failing to post, displaying a solid white LED. The white LED should indicate GPU error, but in my opinion, this is not the case.

What I tried so far was:
- re-seat the CPU and inspect the pins (no bent pins detected),

- clear CMOS,

- run PC with one RAM stick,

- run PC with one RAM stick and without the GPU,

- update the BIOS with EZ Flash (I don't remember last version, but I updated it back in May - now I have updated to ver 3278).

Following the CMOS reset, the PC works for about 45 minutes (which can be observed by increased airflow), then briefly flahes the yellow (it's orange) LED for RAM, then red for CPU and finally gets stuck on white (VGA). Then the PC goes into idle (as I assume from the lack of audible airflow). The chassis and CPU fans keep spinning until I shut off. Without clearing the CMOS, the PC goes straight for the white LED after initial 10-15 seconds of startup. No BIOS screen shows up. I tried DP port on the GPU and in the motherboard. I'd appreciate tips and possible scenarios.

[startlife]

I forgot to add that I do not have the 7950x3d anymore as I sold it and immediately got 9800x3d. I also do not have possibility to test the chip on an AM5 socket motherboard or borrow an AM5 compatible CPU.

[MrAgapiGC]

white led mean the monitor was sleep at the moment of the post or there is no Cable or the gpu is not present. I trent more on the fist one.

since the amd take more time to post, play with monitor menu to keep it awake. on most monitors, example asus, you can ONLY select source, just hover the menu, and that is it. when post you can let go. 

THERE IS NO FIX FOR THIS, since the intro of secure boot on the panorama. i have done this for years since 200 intel chipset. evey day. Nvidia has push some fixes over the years on that area but is not constant. 

this apply TO ALL BOARDS one way or another on all manufactures with the exception of the 1080ti and some amd gpus. 

IF after what i put above does not work you need to check gpu or cable or board.

[startlife]

Could this be an actual issue? I forgot to add that I also booted the PC without any display connected and it also failed to post.

[MrAgapiGC]

failt to post will not give any image or sound in windows. 

fail to post is stock white and green or none

IF THERE IS NOT signal plug to the monitor you can be on windows, but also remember the cpu has also igpu.

play with monitor menu and check. what i do not remember, IF you turn off the psu and there is no cable plug to gpu or gpu is not ok the igpu can kick in.

try what i put and check. 

REMEMBER play with monitor menu when turn on the pc or restart cheers

[startlife · Accepted solution]

Switched the cable from Display Port to HDMI and the PC booted, I was able to enter BIOS and when I restarted and switched cables the Display Port started working again. Either this or the previous CPU was DOA (I ordered a new chip).