Audio System Symptom Troubleshooting - Switches does not function

Switches does not function With the ignition switch ON (II), push the power switch ON to see if power turns ON. Does the power turn on by turning the power switch?
YES | - | Go to Step 2 .
NO | - | Go to procedure ''Power will not turn ON''.■
Find out if all switches do not work, or if there is a specific switch that does not work. Is there a specific one that does not work?
YES | - | Faulty printed circuit board.■
NO | - | Faulty audio unit.■