How to change brightness, and no sound coming through my earphones when plugged in?

[WPCentral Question]

I have tried changing the brightness through the action centre/notification bar by 25% increments but that doesn't work. I also tried to change the brightness through power options in the settings, but that hasn't worked as well.

With the audio, when my earphones are plugged in, no sound comes through. The only sound generated is through the speakers on the desktop computer.