Video starts after locking screen

[Jyotit]

Hi i bought a sony xperia z3. But the problem is when i lock the screen its feature video starts and more over i can hear the voice coming from the other but my voice doesnt goes through But when i record my voice and play it works fine .. Please help 

[_alexdon_]

I am not sure I understand correctly but I think you might have enabled demo mode or got a demo unit. Dial *#*#73556673#*#* and see if something changes.