Question Aorus B450 Video Issue

Jun 15, 2020
I built my PC last November and it’s been working without a hitch until this week when the monitor started flickering and going black. The problem rapidly deteriorated to the point where power cycling the monitor gives me 1.5 seconds of visuals before going black again.

I go into troubleshooting details below but, after eliminating Windows, the monitor, the cable and cable adapter, and GPU drivers, I figured the problem had to be the GPU. The only component I recycled from my old PC was my video card, an ancient Nvidia GTX 750 TI. (I haven’t gamed in years and the current build was an exercise is overkill because I was tired of having a computer that wasn’t up to snuff with my work laptop.)
Anyway, I decided to upgrade the video card and, just in case I want to do some light gaming, I went with the Radeon RX 570 8GB GDDR5. Repeatedly using my 1.5 seconds of screen time, I managed to get the old GPU drivers uninstalled then installed the new card and... The problem persists.

At this point I assume it has to be a motherboard issue but what? This was my first PC build and my limited knowledge has reached its end.

See below for full troubleshooting steps.
Computer Type: Custom desktop
GPU: Radeon RX 570 8GB GDDR5
CPU: AMD Ryzen 5 2600 3.4 GHz 6-Core Processor
Motherboard: GIGABYTE B450 AORUS M
RAM: GeIL EVO POTENZA 16 GB (2 x 8 GB) DDR4-3000 CL16 Memory
PSU: EVGA SuperNOVA G3 550 W 80+ Gold Certified Fully Modular ATX
Case: Fractal Design Focus G Mini MicroATX Mini Tower
Operating System & Version: Win 10
GPU Drivers: Default for the moment
Chipset Drivers: Not sure, can find out with some difficulty
Background Applications: Nothing crazy. windows defender. Can se what else with some difficulty
Description of Original Problem: See above.

— I swapped out the VGA cable
— I switched from a VGA/DVI adapter to a brand new VGA/HDMI adapter
— I tried three different monitors
— After running through a series of Windows troubleshooting steps, I booted to system setup and discovered that the problem is present when viewing the BIOS as well which I assume eliminates a Windows issue
— The GPU drivers hadn’t been updated since I built the PC. I don’t think there have been new drivers for my old card in years.
— As discussed above, I swapped out the video card. I haven’t installed the drivers for the new card yet as I’ve only got 1.5 seconds of visuals per monitor power cycle and that will be a nightmare.
— I double checked that all of the motherboard cables were firmly seated.

The problem was exactly the same regardless of what steps I took above. 1.5 seconds of video then black. Power cycling the monitor gives me another 1.5 seconds.
Jun 15, 2020
Quick update, I tried moving the GPU to a different PCIe slot and the behavior remains the same so that eliminates yet another potential solution.

At this point I have not had responses on any of the forums I've posted to so I assume this is not anything obvious. The only thing left to do that I can think of would be to update my BIOS but I'm nervous as:

-- I've never done that before
-- I only have 1.5 seconds of screen time to see what I'm doing
-- I've heard some of the Aorus BIOS updates are buggy in bad ways?
Jun 15, 2020
No responses so I'm guessing this one is a stumper even for the experts. Since my last post I got a multi meter and tested the power supply and all of the pins checked out just fine.