Audio Systems: FACTORY RADIO - NO SOUND, pontiac firebird coupe, pontiac firebird

Question
94 PONTIAC FIREBIRD COUPE

HI TOM

TWO WEEKS AGO I HAD PROFESIONALLY INSTALL TWO AMPS (HI'S & LOW'S) + SUBS.
TWO DAYS AGO THE SOUND SUDDENLY TURNED OFF. A FEW MINUTES LATER THE SOUND CAME BACK ON.
THE FOLLOWING DAY THE SAME THING HAPPENED BUT NOW THE SOUND HAS NOT RETURNED.

I'VE CHEKED ALL FUSES, CONNECTIONS AND WIRES AND EVERYTHING SEEMS OK.
THE RADIO AND AMPS POWER ON BUT NO SOUND.

WHAT CAN BE THE PROBLEM. DO YOU KNOW?

NEVER BEFORE HAVE HAD PROBLEMS WITH THE RADIO.
THANK YOU  

Answer
Hello Jesus,
Go over all the wiring to look for loose connections. look at the RCA connections for tightness. If the radio has high level (speaker)outputs try connecting a speaker to the radio to see if these outputs work. If they also do not work then something has caused the muting circuit to be turned on. Please give me the complete model number off the radio so I can look up the service data.
TOM,
T&D ELECTRONICS
tdeser@zoominternet.net