Question X470 GAMING M7 AC - Error code 22/78 and CPU debug LED

[albertgong]

Specs
Motherboard: X470 GAMING M7 AC
CPU: AMD Ryzen 7 2700X
CPU fan: the one that came with the CPU
RAM: 2x8GB Trident Z RGB F4-3000C14D-16GTZR
GPU: Sapphire Radeon NITRO+ RX 580 8G G5
SSD: CRUCIAL P5 Plus 1 TB SSD M.2 via NVMe
PSU: be quiet! Straight Power 11 Gold (I don't know the wattage)

The story
I bought the above specified PC second hand from eBay three months ago. As it came without any kind of storage, so I installed the SSD myself right after I got the PC home. For three months the computer functioned without a hiccup.
I bought 2x16GB Trident Z F4-3000C14D-32GTZ RAM sticks second hand from eBay with the intention to fill in the other 2 RAM sockets. Rather than immediately populating all the RAM slots at once, I figured I'd swap the RAM sticks that I already had with the ones that I just bought to see if they correctly get recognized in the BIOS and to test how the PC runs with them in. So I filled the DIMMA2 and DIMMB2 slots with the 2x16GB of RAM. After trying to turn the PC back on, it refused to POST. The CPU EZ debug LED was on and the debug LEDs showed code 78 (ACPI module initialization).

What I did
I removed the two RAM sticks I just inserted and put the 2x8GB RAM sticks back in. Nothing changed. I then tried to boot using only one of the 8GB sticks in the DIMMA2 slot. Nothing. I tried with the other 8GB stick. Nada. I then tried to clear the CMOS using the designed button on the motherboard and by removing the battery. When that also didn't work, I went ahead and flashed other BIOS versions using BIOS flashback+. I flashed the latest version (E7B77AMS.1I0), the oldest version (E7B77AMS.100) and the version that I had before I started all this (E7B77AMS.130). The only difference this made, was that on the newest version, the error code changed from 78 to 22 (OEM pre-memory initialization code). The last thing I tried was to populate the RAM slots in different configurations, from using all sticks at once, to only using one at a time in different slots. I also made sure that the CPU power connectors were securely in place.

What I heard online
I found some posts saying that they fixed states where the CPU debug LED was on, by disassembling the whole PC and building it again or by only taking the CPU out and putting it back in the socket. I'm willing to try this out, but right now I don't really have the time, because I'm in the middle of my exam period. I also find it weird that the CPU would be the problem, when I only fiddled with the RAM. So I started to search for posts complaining about the 22 error code, as that seemed more fitting for my situation. All of them suggested stuff that I already tried above. I'm bummed out that I have yet to find a post complaining about error code 22 in tandem with the CPU debug LED.

While debugging the problem, I did not hear any beeps from the speaker. It only beeped when I tried to boot up without any RAM sticks in. I also was looking for the 1 long beep to confirm that the PC POSTED, which never happened.

Here is a BIOS screenshot that I got from the original owner of the PC. The only thing I changed in the BIOS was to turn on the second XMP profile. I worked with this profile on for 3 months without any hiccups.

 

[albertgong]

It turns out that my CPU died. I've taken it to a service and they have confirmed it. I've installed a new Ryzen 7 5800x3d and now everything works fine, even with all 4 RAM sticks mentioned above installed.