Update:
I finally got it to work. After trying almost everything. I'm going to explain what I did in case it helps someone in the future.
I have done several things, some were probably not necessary, such as modifying the microcodes so that the board accepts some coffelake.
1.
(Probably not neccesary) This is the coffelake mod.
https://winraid.level1techs.com/t/tool-e...bios/32795
Used AllinOne.exe with option 1 on last vendor bios. In this case it was H110M-A-ASUS-3805.CAP (EDIT: Don't do this unless you use a virtual machine, that automatic program to patch the bios introduces a virus into the computer, perhaps more, including an old well-known Trojan, it is not a false positive. It is better to use coffetime, or simply skip this step which is not necessary for xeon to work. )
2. Then I did what dsanke said there (same that Deathbringers said with extra steps). This is supposed to work to fix 200 series, but worked for my 100 series.
https://winraid.level1techs.com/t/are-xe...ets/100144
I used the modified bios from step 1, not a dumped one as dsanke said. Which should work, but in my case when I added a bios dumped with FPT to FIT, warning messages appeared, and these bios failed later, that's why I didn't do it with that dump version, and I used the one from the seller (also modified with step 1).
Dsanke extra steps (with some notes)
"Open BIOS with FIT and save as a xml file, then edit it using a modern editor, not notepad provided by windows.
- search HostCpuWriteAccess, HostCpuReadAccess, MeWriteAccess, MeReadAccess, GbeWriteAccess, GbeReadAccess, EcWriteAccess, EcReadAccess, change the value to 0xFFF.
- search "Reserved value", change the value to Yes. -----------> This is the same that Deathbringer said in this forum
- replace the “ME Region.bin” in decomp folder with the version I have provided (this link: https://winraid.level1techs.com/uploads/...2U64sC.zip)
- load xml in fit, then build. flash outimage.bin.
"
3. Then, I flashed that bios on the chip using the programmer someone lent me. The chip is placed and flashed as shown in this tutorial I found
https://youtu.be/9WprUQ1NMw8 (Its neccesary to erase it before flash). And put on the motherboard with Xeon e3 1280v5 placed. It is necessary that there be a graphics card because this processor does not have an integrated one. If not, three beeps and one long beep will sound.
It works beyond my expectations, I thought I wouldn't get it!
Thanks to Deathbringer for the help and I hope this message helps more people.
P.D. Discovered why FIT wasn't working on the other computer. It's because the name of the folder where it was had an accent.