When I start up car. The screen functions just fine but I get no sound from radio or ipod or CD player (which also doesn't read that it's even there) Once in a while after about 15 minutes or so of driving. Everything just turns on and works fine. Anyone have this issue?

 

Funnily enough something similar happened to me today. Turned on the radio, but there no sound from radio, cd, nav or phone. If you opened the radio screen and pressed the nav sound icon you'd get the driving agreement said to you only if you pressed and held the voice command button on the steering wheel lol. It corrected itself after I stopped and restarted the vehicle. It was most bizarre, and the first time its ever done anything like this. I'm wondering if there is a loose connection on the amp, or if there was a software glitch. I'll be investigating at the weekend.

 

Amp under the passenger seat. Usually the culprit.

unbolt the seat and then check the amp connections. You can open the amp up and visually inspect the board for corrosion or solder deterioration.

Abran got me a used one before that fixed this issue. Although my nav screen was inop too, everything worked after I swapped the amp out.

 

Don't know what vehicle you have, so its hard to say, but on LR3 & RRS I have done a handful of AMPs for similar. I have noticed on the LR3 & RRS when the "no audio" issue is present, when you turn the volume ****, the screen shows "volume" but it never increases or decreases in accordance with the turning of the ****. New AMP fixes that.