Check IC602 #7 (If the pin is in low state, Sound is mute) Normal
Abnormal
Check FA803S
Check D816, Q906 Check IC601 #24, #25 Normal Replace IC602 Check IC601 Input Voltages (5V,8V) Normal Check the coils around IC601 Check IC601 Input Signal Normal Replace IC601 Check the Tuner Abnormal Abnormal Abnormal