panasonic rx-ct980

Hi everybody I have a Panasonic rx-ct980 portable stereo that recently have a problem. I use it in aux mode,connect the mobile phone to it with a cable. I always do this. But recently, when I turn it on, I only hear sound from one of the speakers, low quality sound. when I touch the aux button...

Panasonic RX-CT980 LCD screen has not LED Backlight. I install LED Backlight and Bluetooth. White opaque tape is pasted on the back side LCD screen Solid white plastic. for reflection of LED light POWER for leds: Get Control signal for On/Off led light...