This has happened twice so far in the last month and never before. When I start the car the radio (or cd) is silent and will not come on. The mute indicator is not shown. If I press the mute button the mute symbol appears and dissapears, but still no sound. Very strange.

 

Amp can be defected or remote turn-on signal cannot reach the amp.
If you can use Digital Multi Meter, measure voltage at the input of the turn on signal of the amp in the back (White wire with Violet trace/stripe). Make sure it's around 12V when radio is on.
If remote turn-on signal is correct, switch DMM to AC and measure voltage across any pair of speaker wires for both input and output.
If it reads 0V at the input signal to the amp, the CCC go the problem.
If it reads some voltage at the input signal and output is 0V, amp got the problem.

Best Regards

 

What was the Diagnosis VTbound??