@http://forum.phc.onl/#forbidden#/vbb/f457/know-how-increase-tv-volume-code-3646633-a-744282/
This is an original tip!!! I´ve searched through the *#3646633# , read the tutorial below, but use with caution, don´t do any changes that are not here, like the High Speed Sim option , or your Mobile Phone will be dead!!!