I wanted to write about my own experience with updating the BIOS on a MSI motherboard for anyone upgrading to 3rd Gen Ryzen, as the stuff I read online were not very helpful.

My setup is: B450 MSI Tomahawk, Ryzen 5 3600

Download the latest BIOS Version from MSI's website and then copy and paste only the BIOS file to a FAT32 USB Thumbdrive of less than 16GB. Leave the text file alone, don't copy that.

Rename the BIOS file to MSI.ROM

Shut down your PC, unplug the power cord and locate the CMOS Battery, which is a button cell battery. Either short the two pins beside the battery labelled BAT1 for 5 to 10 seconds or remove the battery and wait at least 20 minutes before reinserting.

Don't install the CPU yet. Plug your PC back in and turn it on. If you use the same mobo as me, you should see that the red LED on the top right near the 24 pin ATX connector for the CPU should be lit up.

Plug in your thumbdrive into the BIOS Flashback USB Slot on the back of your mobo then press the small button above it. The red LED on the top LEFT side of the mobo should start flashing. Do not turn off the PC or wiggle the thumbdrive. If the LED flashes for less than 5 seconds, repeat the steps again, you might have done something wrong.

Let the LED Flash. After a while your PC should restart. Switch it off again and install your CPU and the rest of your components.

You should have successfully completed your BIOS update and brought your non-X570 motherboard up to date. Good luck!

Found it out the hard way, but at least for MSI you need a USB 2.0 with a smaller capacity USB drive (e.g. 8GB) in order for the BIOS flashback to work. I bought an MSI B550 Mortar with a 5900X CPU. the mobo still had the old BIOS so it wouldn't post. I grabbed my regular USB stick, a kingston datatraveler 3.0 32GB stick. the BIOS light lit for like 10 seconds and then shut off. I thought that was quick, tried to post, no luck. I later tried a different old stick I had lying around, an 8GB unbranded USB with FAT32 format. Tried the same procedure and instantly worked. I'm not sure if FAT32 is required but that's what my USB's format is.

Anyway, just a friendly reminder for new MSI buyers

Edit: I also noticed that a lot of people saying that a large capacity USB stick would also work, but seems to be a 50/50. Therefore if you want to be on the safe side just pick up a 2.0 8GB drive for like $10. No one is reporting that didn't work so far

I attempted to use flashback to update my bios and it flashed for 30 minutes before I shut down the computer from the power supply.

I realized later that the manual didn't specify the file system but it needs to be fat32 while my drive was exfat. I reformatted using windows and it still didn't work.

I tried different drives and even formatting a drive using disk part making sure it was MBR and a single partition. The bios was always named "MSI.ROM" and was extracted from the bios zip. I made sure it was not the zip but the file inside the zip (and not the text file).

I even tried with absolutely nothing in the motherboard.

the CPU post light comes on but it does not boot.

The motherboard is a B550M PRO-VDH WIFI. latest bios (7C95v2M) was installed from here: https://www.msi.com/Motherboard/B550M-PRO-VDH-WIFI/support

the GPU is a 7600xt and I'm unsure about the CPU.

My motherboard (msi pro b650-p Wi-Fi) is not posting or have really any signs of life at all so I thought it was a bios issue.

It has a flash bios button on the back so I used it with a usb with the bios file named MSI.ROM and formatted to fat32 and confirmed it was mbr but it still doesn’t work.

I have also tried taking out all components and then trying the bios flashback but still nothing. When I try to do the flashback (with multiple usbs) the light flashes for like 10 seconds then goes off but it says it should blink for 5-10 minutes.

I have tried clearing the cmos and still no update or post.

Has anyone had similar issues with msi motherboards and managed to fix it? Any help or ideas would be greatly appreciated.

I'm using a MAG B550 TOMAHAWK. My BIOS is from May 2022.
https://www.msi.com/Motherboard/MAG-B550-TOMAHAWK/support

I see there are several BIOS update since then with a lot focussing on security patching.

I was planning on just using the M-Flash process to update to the latest, but when I read on Google about the process it says:

"Use a BIOS flash method that fully overwrites the existing firmware (e.g., "BIOS Flashback" via USB if your board supports it)."

It says some motherboards just update/layer the BIOS update, and in case your board has been exploited you should use the flashback process.

Does that sound right, or would the normal M-Flash process be fine and remove any prior compromise that may exist?

Been fighting with this MOBO for some time now. I was able to boot into Windows the last time I tested it, but can't get into the BIOS. I was told that I likely need to flash the bios. I know there's a way to do it via USB but I can't figure out how to do it, nor which specific USB port to use. I've checked the instruction manual and can't find anything.