no sound from cd or radio Pioneer DEH-5

ok I took my friends Pioneer DEH-5 out of his car cause he said it plays no sound from the radio or the cd player. It does turn on. I replaced the wiring harness and tried in my car. It does the same thing. Comes on and has no sound. Any idea on how to fix it? Please help me Your pioneer has a bad channel inside.When one channel shorts they all cease operating untill it's fixed to protect your speakers.
Home of the burnt rubber air freshener. Anything close to catastrophic failure should've triggered and "error message" on the display,do you have any amplifiers using the DEH as a source?
Home of the burnt rubber air freshener. same thing happened with my cd player they told me the memory chip inside the cd player is bad needs to be replaced then will work fine not sure if its the same thing or not, but my pioneer deh-p5901b stopped putting out sound, the display still worked, everything was normal except there was no sound. took it out and it was just that the way i put it in, the mute wire was pinned againstthe frame, just wraped the end in electrical tape and haven't had a problem since.