@GregoryRasputin Thank you for your answer that's nice.
I am in the blur because as much hardware level, the ps4 I know by heart, but software level is another problem for me ... lol
And sorry in advance for my English, being French and not very good at English, I mainly use a translator
added 7 minutes later
Otherwise for information I made a complete transplant (apu, ram, syscon and nor) on a motherboard in blod with 4 missing lines in the unk.
I'm still in blod but the firmware is also corrupt (already before the transplant) but not in the same place because it had no default ram at the origin, just a blod from the firmware ?
I do not know yet.
Tomorrow I would look for corruption and if I can do something about it.
Tired of corruptions of nor ! lol