With a cool head I think I understood what made me confused during the various tests. I made the big mistake of testing the ofw not by completely disconnecting the picofly, but by disconnecting only the cmd so as to mislead the boot and have the original boot. Unfortunately the DAT0 remained connected to the 47ohm resistor and this led me to have a black screen in stock while in reality it was not stock. This led me to look for the mistake where there was none and in fact waste a lot of time. You never stop learningThat NYX error might indicate some data corruption on your SD card.