1.There's no sound when listining to radio but other functions has sound
For pure andriod car radio,maybe the IC of radio is not correct.You can enter Setting-Factory Setting(different manufacturer have different codes,please ask your customer service for codes)-Press the code-Application-Radio-Turn to TDA7388/TEF6686-Apply-Exit,then what you need to do is to reboot your head unit to activate it.

For WinCE car radio,there're two possibilities.There's something wrong with the Reception board or there's problem with the reception audio output circuit.You may need soldering iron and multimeter to test it.

2.The radio reception is very poor.
There's two situations here.
One situation is that the head unit is not able to search any radio station.Then there may be three posibilities.
First check if your radio antenna connects well.If your radio is equiped with radio amplifier,maybe you can try to connect the power cable of the amplifier to the ANT-CON or ACC cable of the unit.
Second,maybe you have turn on the AF search function while the place you stay has no RDS signal.Then you can turn off the AF/TA option to check.
Third,drive your car to an open space to get better signal.

Another situaton is that it can search a few stations but with poor signal and with noise.
In this case,you can try to install a radio amplifier and make sure to supply power to the amplifier that is to say connect the cables correctly.
And it's also possible that your car's electronic circuit affects the circuit of radio and affect the reception.You can install a filter hut to weaken the effect of the car's electronic circuit.
There's one small chance that you have turn on the ST option,some radios maybe effected by the ST,you can turn off the ST to check.

3.The radio itself turn to other radio station.
For this,you can turn off the AF option to check if it's corrected.Or maybe the steering wheel control keys or the changing station keys are stuck.You can have a check and keep pressing these keys to see if they can be turn to the right position.

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