Hi Jorge!
Are you sure that everything is good at it’s place? If yes, Try to clean the contacts, as far as I know, the speaker and the ear speaker both make contacts with the golden pins on the boards. Try to clean the pins (same for on the boards). And make sure that the ribbon cable for the power board is connected to the motherboard.
Ear speaker - Pins on the motherboard.[br]
Speaker - Pins on the power board.