When I plugged in the headphone into the audio jack, there is no sound. The sound is coming from the internal speakers. I just installed System Mechanic and ran a system analysis. I don't know if the registry was changed or what. There is not a problem with the headphone; I tried another headphone and have the same problem. The laptop detects the headphone, an icon shows in the Notifications area saying a device was plugged in.
Inspiron 15 series 3543
Realtek HD Audio Device