Rotel ra-02 amplifier only one channel is working

The chimes an turn signal noise come out driver door speaker . Both front speakers not working could be a blown circuit fuse inside the radio or just blown front speaker channel . Your best bet , take it to a GM dealer or someother qualified repair shop . You have no idea of the complexity of this . The radio can set DTC'S - diagnostic trouble codes , believe it or not !
DTC B1025, B1035, B1045, or B1055
DTC B1025 01: Audio Output 1 Left Front Circuit Short to Battery
DTC B1025 02: Audio Output 1 Left Front Circuit Short to Ground
DTC B1035 01: Audio Output 2 Right Front Circuit Short to Battery
DTC B1035 02: Audio Output 2 Right Front Circuit Short to Ground
DTC B1045 01: Audio Output 3 Left Rear Circuit Short to Battery
DTC B1045 02: Audio Output 3 Left Rear Circuit Short to Ground
DTC B1055 01: Audio Output 4 Right Rear Circuit Short to Battery
DTC B1055 02: Audio Output 4 Right Rear Circuit Short to Ground

Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier have a DC bias voltage that is one half of the battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5V DC. The audio being played on the system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and produce sound. This voltage will vary depending on what type of audio is being listened to, talk or music, and type of music, as well as the volume setting of the system. Low volume and talk settings will measure around 1V AC and less, where constant music may measure 3V AC and slightly higher.
DTC B1287 01: Amplifier Control Signal Circuit Short to Battery
DTC B1287 02: Amplifier Control Signal Circuit Short to Ground
DTC B1287 04: Amplifier Control Signal Circuit Open

The radio provides a remote amplifier mute output circuit to control overall muting of the remote amplifier. The amplifier receives pulse width modulated (PWM) signals on the control circuit at varying duty cycle percentages for controlling muted and unmuted functions of the amplifier. Circuitry internal to the radio monitors the remote amplifier mute circuit for faults and sets the appropriate DTC when faults are detected.

Try interchanging the speakers. If the right channel works, you have a problem with your speaker.

Hi,
I think RA 12 is not existing type, but RA 12xx types exist.
Please try this link, and I hope you will find the relevant documentation.
Good luck!
gylacz

some amps have a switch to bridge them rather than wiring a bridge meaning output is mono check to see if yours has this switch if you do simply put back to stereo

Why would it die from being in storage? Oxide or corrosion on contacts, volume potentiometer, Tape Monitor or other switch contacts.

Try manipulating all controls and switches throughout their ranges many times and see what happens.

Check the heaphone jack. If it works so does the right amplifier. While you're at it, insert the headphone jack multiple times to cycle its contacts, too.

This sounds like there is a problem with the final output stage. Is this a new amp? Is it under warranty?

Dan

Sounds like wiring problems. Unhook everything, then get owners manual for proper instruction

I'd suspect that one of the two output transistors on that channel has gone bad. If you are unsure how to test or troubleshoot this, then you might try replace both the NPN and PNP outputs and catch the bad one that way. If your amp uses an output module then you would of course have to replace the module which would replace all the output transistors on both channels. Good luck. Another thing to look out for, is the emitter bias resistors. They are the large white ceramic ones near the outputs. Sometimes one of those will open up too. They will be of a very small resistance value like .5 ohms (point five ohms) or something in that general ballpark, and have a wattage value of typicaly 5 watts. So they are pretty big resistors. Be sure to check them all even if you do find a bad output transistor. They will often go out with the transistor. Good luck.