Asrock X470 Taichi won't post

Hey there...

I'm having an issue with my Asrock X470 Taichi and I hope someone on here can help me... I've had this motherboard for about 4 months and it has been working fine. Yesterday there was a power outage, and now the motherboard won't post.

When I started it after the power outage, I was getting 5 short beeps. After looking that up, it seemed related to the graphics card. It also conformed to the Dr.Debug post code, which was d6. After I looked, the fans of the graphics card were not spinning when power up the PC. I decided to take the graphics card out (R9 Fury) and put it back in, and the same issue remained. I then decided to reset the CMOS by pressing the reset button in the back. I stopped getting any beeps, and now I get post code either 76 or 7b, don't know which it is. I have a link to a video later.

I thought my graphics card died at first, so I took an old HD 6850 and stuck it in there, and, the same error occurred. But on this card, the fans do spin at least, but, the errors are the same.

I then removed all USB devices, SATA devices, and my sound card. All that remained are my two NVME drives. I then reinstalled my memory and my CPU, reset the CMOS by both pressing the button and removing the battery, and the same issue occurred... Basically it starts posting, and when it reaches 76/7b, it stays there indefinitely. I left it on for an hour. So I have to manually shut it down by holding the power button for a few seconds.

I have recorded a video of the error code, with only CPU, RAM and my 2 NVME drives connected;
https://www.youtube.com/watch?v=LO87wanhPKU

So my questions;
What is the error code? 76 or 7b?
What does the error code above mean? (CPU? Motherboard? Something else?)
How do I fix it?

Specs;
Asrock X470 Taichi
AMD Ryzen 1700 @ Stock
2x16GB G.Skill 3200CL14 @ 3200CL14
Sapphire R9 Fury Nitro+ OC @ stock
Samsung 970 EVO 500 GB
Adata 8200 Pro 1TB
EVGA SuperNOVA G2


Thanks for the help.

Hmm,
76 - PCH DXE Initialization (PCH module specific)
7B - Reserved for future AMI DXE codes
D6 - No Console Output Devices are found

I suggest to check the power supply without mainboard.
If your have no experience and/or tooling for doing that, let somebody do it for you.
Anyway, "How to Manually Test a Power Supply With a Multimeter":
https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

Or get another/new power supply for a test, if PC hardware is still functional.

Even if it works with the FX8320, that is no guarantee it would work with your Ryzen setup, different power requirements, power envelope and VRM. PSUs are a lot more complicated than a run of the mill power adapter, for example, it could be reading at 12-13v (optimal) on a multi meter but still not work with a system because it's ripple (fluctuation) is too high. There are a fair number of things that can go wrong with a PSU, many of which do not result in problems you can detect with a multi meter.

Still, it is worth testing it with the older hardware, if it won't allow POST there then you know for certain the PSU is the issue.

You can also try a full CMOS clear on the Ryzen setup, pull the CMOS battery, disconnect from power, press power button for 10 seconds then clear CMOS with the jumper and leave it disconnected from power for 1 hour. Good luck

Ok... So, I decided to make it heavier for the power supply, and put the Fury Nitro on the FX8320 system, and, fans don't spin, no boot... No beeps...

So I guess it really is the power supply.

Thanks. I will do that, but in the mean time, I think I'll simply buy another PSU, simply because the RMA process generally takes so long...

Any recommendations? I'd prefer to spend around $100 but can stretch to $120 if necessary.