I recently change iPhone 5s battery after watching video on YouTube for 3 days.
It went well and after fixing the new battery and closing the screen i found the phone sound lost.
I opened the screen to look inside and found the touch ID protector was no fully inserted. So i reinsert until hearing a click sound. Found out it was the main culprit for the no sound .
Putting back the screen do testing and use the phone awhile and getting no sound again. So once again have to take off tge screen and secured the plat in place. Then i realize there was a little dust on next to the home button and wipe it off. Test the sound and it was working again. Shut the screen on. And been using my 5s for 2 days with out complain.