Recover BIOS after update failed

[mapomme1108]

Hello,

I have an OEGStone/Intel DH61DL motherboard. I have updated the BIOS but it failed.
Now the motherboard powers up and I can access the BIOS interface but it does not boot any operating system.

If I try to update again, it always fails.

The BIOS chip ID is : $EF, $40, $16, $15
I have detected, read and backed up the non working BIOS with a usb programmer CH341A.
The software I use is CH341A Programmer v1.34.

I have write the chip with a BIOS file from OEGStone website but the screen stays black.

I have write back the non working BIOS, and it is the same problem as when the update failed:
the motherboard powers on and I can access the BIOS interface but it does not boot any operating system.

I am looking on the internet for a BIOS file to restore the BIOS
or
someone that is able to correct the errors in the backup file of the corrupted BIOS.

Thanks in advanced for your help