Aptio IV modded BIOS Checksum error with aflash3

Hello guys,

I have a Medion P6634 laptop of which I wanted to updated to CPUIDs in order to support newer CPUs.
To get a backup of the current running BIOS I used aflash3 (provided by Medion). All other tools such as AFUDOS and UNIFlash didnt work.
Using MMTOOL 4.50.0.23 I added a new CPU ID file and saved a new version of the Rom. I also tried removing 2 old IDs (to create space) and added the new one.

When going back to aflash3 (in Dos using a USB boot stick), I get the message "Error!! BIOS CheckSum Error".
What do I need to do to make this work?

Any help / guide is greatly appreciated.

I guess it helps if I include the files.
Attached is the original BIOS file (301original.rom)
The updated version that gives the checksum error (301updated.com)
And the CPU Microcode file that I inserted (cpu306A9_plat12_ver00000021_2019-02-13_PRD_A8DF9213.bin)

I hope someone can point me in the right direction.
Thank you!

P6634files.zip (2.72 MB)

I tried playing around with UBU, but the latest version I get the message "unknown platform bios" and it quits.
Using an older version (1.69.17) I am able to get in and change up some of the MicroCodes, but not the possibility to add one on top of the existing ones.

Ur backup is not ok, its only partial.
Its AMI IV UEFI.
Get an official bios update or perform a full backup with AMI IV tools or Intel FPT tool.

More info on it, perform some searches in forum or around the web and get yourself more instructed!


EDIT: "Or is that also not right?"… Yes this one is right, maybe not ur actions humm?
Well keep digging then, keep up the good work.

Actually the original bios that I included in my upload earlier comes from the Medion website:
http://cdn.medion.com/downloads/treiber/…_p6634_v301.zip

Or is that also not right?

I had also done some dumps using 2 other tools, but afterwards the tools such as MMTool gave an error message when opening. But those files were all also 2Mb each. So I’m thinking the “original” bios file should be ok as well with only being 2mb.

Would it alternatively be an option to program the BIOS directly using a CH314A programmer?

Anyone any ideas? …