I had the same problem with my S4 mini on a rainy day while I was waiting the bus. While I was browsing suddenly the icon and the sign for headphones connected showed up without any headphones being connected.
What I did is to put the headphones jack and twist it a couple of times. It worked![]()
This is not a settings issue. The contacts inside the headphone jack are shorted out, which tells the phones a set of headphones is connected.
This can happen due to a tiny drop of water, humitity, a sliver of aluminum foil, etc.
The easiest way to clear and fix this issue is to blast a bit of air from a compressed air can into the headphone jack. You can get compressed air cans for a few bucks at any local office supplies store, Fry's, Office Depot, etc.
Just a short blast or two will clear the problem.
Or Blow air with your mouth for few times!!
Although I do not have any earphones connected to my Samsung Galaxy S3, the phone thinks I do and has no sounds audible. If I do plug in earphones, they work fine. But, unplugging them does not remove the earphones connected icon, nor does normal sound return. Is there a setting that will correct this problem, or should I seek repair? I have tried powering down and re-booting, with no success. Any suggestions?