PC Does Not Recognize GPU / Won't POST

[ScottRevere]

Hi all,

 

I've had this PC that I built for about 4 years, and it's always worked fine. Two weeks ago, when I went to turn it on, it randomly wouldn't generate a display. The PC itself powered on, fans spin, RGB lights up, video card RGB lights up, but no display is detected and the monitor says no device connected. I checked the motherboard, and noticed that the VGA ez debug led was lit. I tried reseating the GPU and RAM multiple times to no avail.

 

I finally decided to replace the motherboard. On the new motherboard , I am having the same problem. The VGA error light on the new motherboard is lit up. I have since replaced the PSU, GPU, motherboard, DP/HDMI cables, and nothing works. 

 

This inconsistency is absolutely driving me crazy, because about 2% of the time, it actually does boot up to windows normally. However, I tried launching a game on steam, and the visual performance rapidly deteriorated until the screen went black, so even in those rare moments, something seems wrong. Here's what I've tried, in summary: 

 

- tightened and re secured all cables 

- reseated RAM and GPU

- tried different RAM slots and only using a single stick 

- tried different DP ports, cables, and the HDMI port 

- tried different monitors 

- tried different PCIe slot 

- replaced motherboard 

- repasted cpu

- replaced PSU

- replaced GPU 

- unplugged case fans, all USBs except for main power cable and 1 monitor 

- reset CMOS

- made sure monitors were on before turning on PC

- Tried to boot without storage (same error)

- hooked up to my television with HDMI 

- tried plugging into different wall outlet (you can tell I'm getting desperate here)

 

At this point, I have a 75% of a brand new computer, which is maddening that I still get this error with a new PSU GPU and motherboard. The cpu is basically the last thing to test, but I'm skeptical that is causing the issues. 

 

TLDR; PC powers up but GPU does not detect a display or PC does not detect the GPU 98% of the time. Worked fine for years with no changes. It randomly has worked a few times recently. When I power on the RAM led is orange for a second, CPU led goes red for a second, and then VGA led goes solid white and stays that way. 

 

Equipment: 

Ryzen 56000x

EVGA 3080 ftw3 ultra (OLD) > swapped in 9070 XT power color hellhound

Crucial ballistix 16gb

MSI MPG x570 gaming edge wifi (OLD) >Swapped in Asus rog strix b550-f gaming WiFi ii

Corsair RM750x (OLD) > swapped in nzxt gold c850 3.1atx