I upgraded from a Ryzen 5 3600 to a Ryzen 5 5600X3D on an MSI B450 Tomahawk Max. The 5600X3D gives me no display, and while reinstalling the 3600 I dropped it and bent or broke several pins, so that CPU is no longer usable. I'm now trying to update the BIOS using the motherboard's Flash BIOS button. One 16GB FAT32 USB drive, containing only the BIOS file renamed exactly to MSI.ROM, makes the button blink three times and then stops. A 2GB Kingston FAT32 drive does not blink at all; after a few seconds the system powers on but still has no display. I've checked the filename and tried multiple drives. Is there another step I'm missing, or do I just need to keep trying different USB sticks?
3 Answers
The 5600X3D needs a BIOS version that specifically supports it, and the original B450 Tomahawk Max and the newer B450 Tomahawk Max II are different boards. Double-check the model printed on the motherboard and download the matching file from MSI. Don’t use a BIOS file for the non-Max version or Max II. Also make sure Windows hasn’t hidden a second extension such as MSI.ROM.ROM.
For Flash BIOS on this board, remove the CPU, RAM, graphics card, and all other USB devices first. Leave only the motherboard connected to the power supply, with the 24-pin and CPU 8-pin cables plugged in. Format a small USB 2.0 drive as FAT32, extract the correct BIOS file for the exact B450 Tomahawk Max model, rename the file to MSI.ROM with extensions visible, and put it in the drive’s root directory. Use the dedicated Flash BIOS USB port on the rear I/O, then press the button. The LED should blink continuously for several minutes; three brief flashes followed by stopping usually means the file or drive was not accepted.
You probably don’t need to buy a pile of drives, but Flash BIOS can be picky. A basic 4–16GB USB 2.0 stick formatted with the motherboard’s required FAT32 layout is often more reliable than a newer large drive. If the flash still fails with the CPU removed and the exact file, try clearing CMOS and repeat the process. The damaged 3600 cannot be used as a fallback if pins are broken, so successful BIOS flashing or a repair shop may be the practical next step.
I tried three FAT32 drives and confirmed the filename is MSI.ROM without a hidden extension. The next things I’ll check are the exact board model, the dedicated USB port, and flashing with no CPU installed.
I hadn’t tried the process with the CPU removed because most guides didn’t mention it. I’ll retry it with the board stripped down and verify that I downloaded the BIOS for the exact board revision.