Grazie Andrea per la tua risposta.
Guess what, it was disabled (grayed out) only half a day. from now on it is working again.
I will repeat as prposed if it reappears.
I did it, too. Worked.
...Thing is: After 12 days the problem reappeared!
I did it with a hot air gun instead of a reflow station. Set it to around 300 °C but kept distance of 1 - 2 cm to Wifi chip. Maybe too little heat?
Did it reappear in other guy's cases? How did you solve it?
PS I filmed the whole thing with my gopro to upload a video guide which I fortunately haven't done yet. oO
Mille grazie, Andrea! I completed the repair thanks to your awesome Guide. Could it be you forgot to describe disassembly of the camera + surroundings? I took it out, too.
However, thank you,