Thanks you very much for this "hard to find" service manual.
Will help a lot in repairing this receiver.
Text excerpt from page 19 (click to view)
4 Troubleshooting
4-6 No Sound
Does the DC 5 V appear at Pin 4 of IC803, Pin 5 of CN806? Yes Does the sound input signal appear at Pins 6 and 11 of IC803? Yes Do the sound signals appear at Pins 3 and 14 of IC803? Yes Does the DC 2.5 V bias appear at Pin 16 of IC503? Yes Check CN814, CN815 outputs.
No
Check IC803, IC804, VR841 and related circuit.
No
Check Pins 1 and 2 of CN806 and related circuits.
No
Check IC803 and related circuits.
No
Check C815, CN813, R821, R822, ZD803 on the Audio PCB.
