Now to the results.
flashed in the file and verified the flash went good. worked perfectly, went into FACTORY MODE.
but now to the odd thing:

While in factory mode, and entering the service tag, the computer dies randomly before I got to save the service tag, it just rebooted in the middle of entering it.
Tried again, went into factory mode, started entering service tag but it then died randomly again. (both times on DC power).

Now it just turns on, fans on full speed, caps lock LED on.
no beeps.
Display test (D key) works.

Tried...

Dell Latitude 7300.

Tried to unlock bios using the 8fc8 patch, but didn't work. Reprogramming the original bios doesn't work either.

using CH341a with NeoProgrammer 2.2.0.10 which identified the bios chip as 25Q256 but quess 25B256 and 25Q256 is the same thing when it comes to programming.
Reading BIOS was done by read + successfull verify, so the content should be exactly whats on-chip.

The computer immediately turns on when attaching DC power. Then it just loops with black screen, turns itself off, and then on again after like 30 seconds, and does...