IPhone 4S no sound with music?

My speakers are fine, calls make noise and some apps make noise, phone is not on mute. If I try and listen to music it says it's playing but you her nothing, this includes YouTube and my music from my library and any other music apps. Happened randomly, I was listening to music, paused it to go to the washroom came back and it didn't work. I've restored to factory settings, and still same story. If I plug headphones or speakers into my phone it works.

Turn up the volume (y)

What do you expect? It was made by some 10 year-old Chinese kid making a penny a day.

See if turning up the volume works first.