Stereo has power but nothing plays through the speakers

I was out the door on the way to work and when my truck started i turned the radio on and it had power as well as the clock and charger i have in the outlet but nothing would play through the speakers. It worked perfect the day before. I checked all the fuses and none of them were blown, just looking for a little help to trouble shoot it

 

Defective stereo. There are no fuses for speakers.

 

Obvious ruled out? Volume knob working ok.. you should see the on-screen volume bar increase..
Speakers are plugged into the back of the unit, have been messing with the wires behind the units area?