At the start of 2022 I went about building a new desktop. The system came out well in the end, and I am still using it although it has always had one issue that I mentioned back then… When the system tries to reboot it shuts down Windows, then the fans spin up, and it never resets the CPU. I always assumed this was due to the fact: mistakes were made and when I needed a BIOS update to support the AMD Ryzen 5800X on that motherboard, I flashed the X570 Pro4, NOT X570M Pro4 BIOS. I decided the time had come to fix this and flash the board back to the proper BIOS.

Note: I will use BIOS and UEFI interchangeably here, I know they are technically different.

AsRock gives out the BIOS updates, and you are supposed to load them on a USB drive and select the “Instant Flash” utility in the UEFI menu. The issue is the system thinks it’s a X570 Pro4 (not M), and refuses to flash to the M variant. I saw some people on the internet mention you can use the “AMIBIOS and Aptio AMI Firmware Update Utility” utility to force a BIOS flash on the system and get around this. I did that, and then… the system never booted again… I don’t know what went wrong, or if the utility flashed everything correctly, but I couldn’t get the system to boot.

This led me to another rabbit hole, flashing your bios with an EEPROM writer. There are several to choose from, and of course I got both. The CH341A, and T48 TL866-3G programmers. I tried for a while to get the CH341A to work, and it may have in the end, but I had a better time with the TL866 software of XgPro.

I unplugged everything and took out the BIOS battery. At first, I tried to use some of the tools that came with the flashers to grab the chip on the motherboard. Here was the first hurtle, the chip was a surface mount part that made it very difficult to connect to and every time I tried to read the chip I got an error. Then I found this post, https://www.reddit.com/r/ASRock/comments/1cz1bcz/guide_asrock_spi_tpm_j1_bios_ph_pinout_for_ch341a/, which mentioned the SPI_TPM_J1 header on the motherboard actually hooked directly to all those pins and could be used to flash the chip much easier.

Connecting to the pins proved to be a bit difficult because of how small they were. Turns out they are 2mm pitch instead of 2.54mm (more standard), so I had to order https://www.amazon.com/dp/B07FKLKM7L as one of the commenters suggested to be able to connect easily to the pins. Then I did some janky stuff with jumper wires to get it into the TL866 programmer.

The programmer also uses Windows-only software, and I was on my Linux laptop. I installed a Windows 11 VM and forwarded the USB device to use the software. The Reddit post mentioned that they had a similar motherboard and needing to use the 1.8V adapter for their Winbond W25Q256JW BIOS chip. I assumed the same but when I went to read the bad BIOS back, I was given “ID Check Failed 0xC2 25 39”. Which turns out to be a 3.3V Macronix MX25L256, with Claude assuming it’s a MX25L25673G. I pulled out the 1.8V adapter and hooked right to the chip. I still failed to get an ID with the built in tool, and when I forced the chip type, I was told one pin wasn’t connected right. I adjusted the pin and hit READ again and got a hit, the ID didn’t match the software’s record for that chip type. I ended up disabling ID Check and then doing a read. AND I GOT DATA! This showed my wiring was good enough.

From there I went and got a new BIOS from AsRocks site. Seeing the BIOS file was exactly 32MB, and the BIOS was 256 megabits = 32MB, I felt confident that I could write this whole image and it didn’t have a header or something that would break directly writing this image to the chip.

I hit program and crossed my fingers. After a minute of erasing, then a minute of programming and verifying it said it was done. I unplugged my laptop, and plugged power back in. The system came on when I hit power, but again no POST. Then I waited a minute, and it powered off, this time, when I powered it back on the system came to life with the AsRock UEFI screen! I had to re-enter UEFI settings but we are back!

The last and final irony… on the correct BIOS, up to date, the system still fails to restart…