You need to use white noise to test and mono if playing music.
Look for a tweeter that is not working.
Make sure the connectors are all clean and tight.
Use contact cleaner and clean the volume and balance controls. Shut off power and twist knobs multiple times.
Look for a tweeter that is not working.
Make sure the connectors are all clean and tight.
Use contact cleaner and clean the volume and balance controls. Shut off power and twist knobs multiple times.