ASUS M5A99X EVO BIOS flashing/programming


I have a M5A99X EVO rev 1.01 motherboard which apparently seems to have a corrupted or defective BIOS chip. The BIOS is an AMI BIOS
I have been taking a look and this is a Winbond 25XXXX chip (Sorry, I cannot see the other numbers in the chip) which should be compatible with a CH341A USB programmer found in some online stores. I took a look at an Aliexpress one and thought about getting it.

The problem is that, as far as I know, it’s not possible to download the latest BIOS from the ASUS website and flash it directly using the programmer. Is this possible?

Or does the BIOS have to be converted to a specific file format before being able to program it using the programmer? I have tried to look a bit on the internet and some people talk about BIOS dumps, which don’t seem to be the same as BIOS ROMs from the manufacturer websites. The motherboard bios on the ASUS website ends in a .ROM extension.

It’s impossible to boot the computer and flash the BIOS using AFUDOS or similar. I have also tried to connect a FAT32 2 GB USB memory stick with the latest BIOS renamed as AMIBOOT.ROM, turn on the computer, but no luck. The USB is never accessed at all.
So I think using a programmer is the only option available. In case the chip is broken, then I would need to buy a new virgin BIOS chip and program it if needed.

Could you please provide me information about what I need to follow? The programming BIOS tutorial here doesn’t have screenshots attached and no new information since then. But otherwise that making a current dump of the BIOS chip and flashing a new working BIOS, or dump, should fix the problem.

This is the programmer I found, all are identical anyway:…earchweb201603_

This is the M5A99X EVO latest BIOS download:…

Thank you so much in advance…


If your MB is r2 version bios can be downloaded from :…/HelpDesk_BIOS/

As for flashing, I have flashed bios file directly to bios chip using raspberry pi and open source program Flashrom I have flashed 2 motherboards like this. Just picked bios files from manufacturer and flashed them to bios chip. I presume that would work for You too.