HP Mini 800 G5 - Transfer identity & WinLic between two mainboards

[wshadow]

Hi,

I got two HP Mini 800 G5 machines, both 65W mainboards (have all 12 FETs populated on the CPU power rail).

One board is always throwing errors in MemTest86, no matter which known good CPU/RAM combo installed. Board is fried. Period. Will be scrapped.
The defective board contains a Win10Pro license in BIOS.

The other board is working perfectly fine, but only includes a FreeDOS "license".
I want to transfer the Win10Pro license from the fried board to the working one. If that includes transferring S/N etc, I'm fine with that, will do a case swap as well.

What I did so far:

• Desoldered both BIOS and PRVROM chips from both boards
• Made a backup of each chip (of course)
• Overwrote the complete PRVROM contents of the working board with the contents of the defective board
• Replaced 0x01000000h thru 0x01FFFFFFh (16.0MB, just before the "-Configuration-" string starts) of the contents of the working board with the exact region of the defective board in the BIOS ROM dump, flashed it back
• Soldered back PRVROM and BIOS ROM to the working board

The result is that the original descriptor, GBe region and ME region are retained, only the BIOS region is replaced.
Now the board powers up, but throws an error at me that there is a problem with the Endpoint Security Controller.
In the past, I did similar things on HP 820 G1/G2 laptops (which still had the "$LOGO" string in the beginning of the BIOS region) and it worked perfectly fine.

What have I done wrong?
Is it possible at all what I am trying to achieve?

Thank you in advance

[DynaxSC]

I'm no expert in BIOS modyfying, but my impression is that your approach is too complicated. I'd rather would try to transfer only the licence key from the defective board to the working one, so the most small amount of data, instead of what you are doing. The business pc vendors like Dell, HP, Lenovo do lot of security magic in the bios'es unlike vendors like ASUS, MSI, GIGABYTE or ASROCK. I know that at least DELL pairs bios'es with chipsets burning some fuses in the chipsets at production finalizing, so you can't swap bios images between two same type, but different copies of the boards. Maybe here is a similar issue. This burning of fuses is for security reasons for business uses. Can't be overcome, as the fuses in the chipsets are one time programmable and not resettable, only way to overcome would be to exchange the chipsets too. However I'm not expert here, so I might be wrong.
There is also some nice software tool call "Read Write Everything" or similar name. This tool can read and write the register areas in Bios with the license keys, maybe you could try this, instead doing the complicated way. You would have to google how to do it, there is a special register which holds the key, as I do not remember this and I'm not at my pc now. This piece of software is very helpful, but it needs to run to do some registry hack, otherwise it will not run. This hack or better modification is to be found with google providing the error message on start. This way however might only work if you manage to run the defective board so long, that you can save the key register somewhere.