回答“Why has the left side of my beats x stopped working?”Is it the device or your phones. Use a test meter on ohms and test the resistance of each earpiece.
回答“Motherboard or Battery problems?”Is the phone drawing any current from your PSU ?
回答“Turns off in a few seconds after turned on.”Overheating problem. Worth a stripdown and reapply the heat sink compound to the CPU / heatsink.
回答“ceramic fuse is blowing in power supply board”Check for short after fuse. Voltage dependent device (if fitted, a blue flat disc size of 1p coin) will go short, as can the bridge rectifier or the smoothing capacitors.