So the media sounds have completely stopped through the loud speakers in apps like YouTube, BBC news, Facebook etc. The audio jack is still working. The phone's diagnostics do not detect any problem with loud speakers - I am able to make phone calls. I have even tried the app called Sound About but to no avail. The only physical issue with the phone is that the screen is slightly peeling off from the right corner which I have a tape on to keep it in place. Then again the diagnostic is able to play an audio through the loud speakers just fine. Anyone has any clue?
