Is the sound output from YES both channels (L, R)? NO No sound from either channel. NO Compare the L-ch and R-ch to locate the defective point. YES
Normal Is the audio signal Is the audio signal output YES (including sampling YES at pin 14,pin 15, pin 18 output components) and pin 19 of IC171 during output to pins 1 and 7 of playback? IC581 during playback? NO Check IC581 and its peripheral circuits. NO Check IC171 and its peripheral circuits.
Is 9V present at pin 32 of IC171?
NO Is 9V present at pin 13 of IC901? NO Check IC901 and its peripheral circuits. YES Check the connections between pin 32 of IC171 and pin 13 of IC901. YES Check the power amplifier IC301.