(You should answer in English as he does not speak French, and I doubt that Google translate will do a correct translation of technical information..)

A rough translation:

MadMax2023 (./2) :
Hi,
I you had manage to install this new optical bloc (which seem really similar to the original one on your pictures) I thins that there won't be any problem on this side.
But, it is generally not sufficient to just replace it by a new one, you will also need to set! It not ever install'n'play... hopelessly.
In your case, since reading the disc does not work, I should try to set the laser diode potentiometer. But be careful, you will need to do it really gently and use an ohm-meter to know exactly the current value setted. (that mean that you should do slight adjustment, not big changes)