ps4 system recovery problem ( safe mode loop ) !

[mitcha]

hi, i have a 1216 ps4 who can power on only with a cd game ( i just insert half of the cd and the ps4 power's on ) because the power button is desoldered.

console ask for 7.50 update on the safe mode option 7 , so ;

-i put a 7.55 recovery system ( 1go )
PS4/UPDATE/PS4UPDATE.PUP nothing
-also a 7.50 recovery system ( 1go)
PS4/UPDATE/PS4UPDATE.PUP nothing
-also a 7.50 update system (490mo )
UPDATE/PS4UPDATE.PUP nothing

initialising goes 100% ,then preparing system update 100% , after that the ps4 reboot and goes direct to "connect dualshock ....and press ps button"
if pressed we go to safe mode again and again.

what i've tried
-changing the hdd.
-format exfat, ext4, ntfs.
-mbr and gpt.
-changing the usb stick ( where the recovery system is )

reminder : the ps4 has no power button, it's desoldered, but can boot with a cd game.
is this related ?

any hint's are more then welcome i'm out of ideas.