I made a mistake, I inserted a disk II controller le wrong way...
several chips burnt... including some on the analogic board of the Disk II drive....
the analogic board of the disk II is repaired and works
all the burnt chips on the Disk II controller replaced including the P5 prom (all are working)
the Apple try to boot but the engine never stop and it never read
I tested all chip
(everything works fine with a second controller)
(even if I swap the chips between the good and the failing board)
there are no traces of burnt tracks on the board
any idea of the failing element ? perhaps a transistor ?