I have a Grand X Max 2 and I had taken it apart to replace the battery and charge port. My sound worked fine before I took it apart, I know for a fact I didn't break anything because I was too careful. Well when I put the speaker back in, I notice when putting the screws back in it just didn't sit flush and kept playing with it and taking it out, back in and finally, I guess it made contact somewhere and my sound came back on.