The sound comes and goes at Samsung laptop with Windows 8.

The Samsung laptop is a model np350e5c and the operating system is Windows 8.0. It began one day when there all of the sudden wasn't any sound when playing Youtube videos and a few days later the sound also went off when playing music at Windows Media player.

Sometimes the sound works fine and then it will stop working for a few hours.

Tried to update the drivers but the sound still isn't working consistently. Any ideas about what could be the reason?