Test whether wave band switch voltage is available with CPU �,1�,41�,42 pin. Test pin VT output voltage is normal or not.
NO YES
Change CPU.
Check whether AGC voltage for +5V power supply of TV tuner is normal or not. Check the TV turner VT voltage is normal or not. Check 5V power supply and AGC circuit, and also check the circuit of VT voltage.
NO YES
Check whether circuit of pre-central amplifier and periphery of LA76810�,50 pin is normal or not.
NO YES
Check periphery of �,50pin for pre-central amplifier.