Where is link to the BIOS dump you mentioned in post #15? Can't be post #13 link, you said you are not author?

Yes it's my BIOS.
It's motherboard after return and someone patched bios for non k OC and it was flashed to my motherboard...
I checked BIOS process clean CSME patch in three steps:
1. flash A91 BIOS (no BIOS reset, OC works)
2. only add clean ME with the same version included in BIOS
no BIOS reset after save of settings, OC not works, not enabled BCLK OC option in BIOS.
Version of ME in BIOS is showing.
3. change variable in FIT in tab of ME Kernel to Reserved.
Motherboard starts up with message ME FW is invalid.
Version of ME in BIOS is showing as N/A
1. It is possible MSI is checking ME deeper than Intel Tools?
2. Is that variable (ME Kernel - > Reserved) is needed to run Xeon?

Maybe you are not building ME via FIT properly? Did you compare XML with before and after and see only 3-5 changes at file/data locations only not settings?

As far as I've seen, and made BIOS for this, yes reserved was required and that was the only change needed (Plus certain older ME versions)

Patch for non-K overclock likely involved ME changes, I will not use that file then, thanks. I'll just build from stock BIOS, sorry I've been behind, hopefully will try to get made tonight.

You never answered my question in post #8 - are you properly resetting ME state between BIOS/ME flash tests (ie greset or full power drain for 1+ minutes)?

I use -greset on Windows.
CMOS battery is out and I'm waiting about 2 minutes and discharge capacitors (many times hit power button without voltage).
I checked binary difference between file form step 2 (clean ME) and reserved yes in step 3 it has only changed 4 hex values and the rest is identical.

Thanks, good you are resetting ME state. I am not sure what your last sentence in about, changing one setting is probably correct to only see few bytes difference.

Do you have flash programmer? If no, how are you sure ME is being written? E
specially now that you said ME shows N/A or does not give MEInfoWin, this means corrupted and can only be fixed if FD is unlocked to write to ME (via FPT), or with flash programmer, since if corrupted and FD is locked, FW Update tool can't write to ME

I am working on BIOS now for you x4 (2 old BIOS + 2 new BIOS each with same ME version and ME Reserved Yes and No), all with single 506E3 microcode that I know works with these CPU's (74, I know C2 works too but we try 74 first)
Maybe reserved yes and no both work, but only with reserved NO you can bclk overclock (Possibly, depends on board)

I make this steps again, it could be helpful

step 2# insert clean ME v. 11.0.0.1191 (it shows this ME version in BIOS)
step 3# enable Reserved to yes (ME ver not showing in BIOS, listed as N/A)

I do that on 2 version of BIOS A91 and A40

But version A40 is saving BIOS settings with N/A ME and works like normal BIOS

There was only one change in config files
That is Reserved option in ME Kernel from No to Yes

ME N/A means corrupted ME, either bad flash or bad edit to the ME when saving/building BIOS.

Here is 4 test BIOS for you, be sure to reset ME State via greset or power drain for 1+ minute after each flash
https://nofile.io/f/mGyTACO6dfT/MSI+Z170-A+ME+Test.zip

These all have Rev 74 microcode, and 2 x 506E3 old codes removed, FIT table corrected, and then ME Yes/No for each version.
They left in 506E3 Rev FF, in all BIOS, along with newer version too in each of 506E3. I removed both, put in Rev 74 only, fixed FIT table after that.
Maybe they leave in FF version to disable something, no need for that when they put in new revision 506E3 both times, but still leave that older one too (It's not ES ucode, so no reason to leave other than bad intentions )

Intel Management N/A in BIOS after fpt -greset and CMOS battery out on 2 reserved yes bioses

I have on this BIOS message on boot about invalid ME

With reserved no not booted Xeon

When I changed CPU to Pentium G4400 and go to BIOS the version of ME is 11.0.0.1191 on 2 BIOS with reserved no

I found BIOS which save settings and no showing any errors with ME N/A on boot it is A4 version

Is invalid Intel ME reduce performance of computer and system?

I will try flashing next day because I ordered SOP8 clip, maybe it help something

That is strange, maybe you are right and MSI did something on this board BIOS, or forgot to do something, that causes that to fail?
But, to be honest, I am not sure what/how ME reserved should appear in BIOS, maybe N/A is correct. Does Xeon work or not on those BIOS, any of the four I sent?

ME reserved might only be needed if you want to attempt overclocking (Bclk), test Xeon on the reserved NO too

All my or your bioses with Reserved NO runs xeon with ME N/A in BIOS.
All bioses patched with me_cleaner with option -s runs Xeon but ME is N/A.

I'll made bios A40 with Reserved NO and this old version is not checking ME state.
I figured the this BIOS works with xeon without BIOS reset, any messages and settings are saved ;)

BIOS settings are reseted after save on BIOS maybe higher than A40.
I made A50 BIOS probably without option Intermediate Files and motherboard is now bricked

I tried to insert Pendrive formatted to FAT32 with file named AMIBOOT.ROM, and I hit Ctrl + Home, the USB keyboard is working but PC shutdown about 2s (it's on Pentium G4400).
I'm waiting for SO8 clip.

Is it possible to run recovery flash on AMI bios and how name files?

I think MSI have specific recovery options and functions, look around on their forum for recovery and you will find the method and tools.

So you had it running with no ME in BIOS, who cares about that, you want Xeon running with mod BIOS, you got that, why more changes needed other than that I am confused now?
I thought all this due to you couldn't run Xeon properly

Xeon works now without BIOS reset.

I'll check perfomance with G4400 with Intel ME enabled/disabled and Xeon ME disabled.

Only way to recovery is CH341A when SO8 clip arrive to me.

You can't boot to CD or DOS?

Yes,
Board run only for 3s and lights up usb keyboard for 1-2s.
I made FAT32 8GB pen drive with AMIBOOT.ROM and all 6 other names suggested from MSI site and the board turns off.