First of all,a big thanks to Dark_alex :)
Thanks to him I learned alot.
After reversing the whole 3.71 M33-2 custom firmware(you can have a prove if you want),
and knowing that Dax is retired,I decided to release the custom firmware.
The Recovery is the old one,soon update will come with new one,my own.
Not much changed from 3.71 to 3.72 so I just had to adapt the code to the new firmware.
The updater is the same as Dax's(all reversed by me,too).
No 1.5 kernel included.
Put the eboot and the umodule.prx in the folder PSP/GAME/UPDATE and put the oficial 3.72 eboot with the name 372.PBP in the same folder.
The sony code will install 3.72, when it says to press X,You MUST PRESS X.DONT SHUTDOWN!
IF YOU DONT PRESS X YOU WILL BRICK!.
Tested on PSP Fat 3.71 M33-1 and 3.71 M33-2 same for SLIM.
Again thanks to Dark_Alex (for the good time) and Coolj for being my good betatester.
NOTE: BY _HellDashX_ I am only betatester and helped with some stuff.