[drussell]

Troubleshooting - Audio:

If there is no sound, check the volume control voltage at pin 1 of Plug P302 while the volume is varied from MINIMUM to MAXIMUM. The voltage should vary from about 0.67v at MINIMUM to 6.17v at MAXIMUM volume. If the voltage is absent troubleshoot the Remote Receiver Board (MCR017A) and the Tuner Control Board (PW2500). If the volume control voltage is good, inject an audio signal at pin 9 of the Audio IC (U201). If there is no sound at the speaker, check the Speaker, Plug P201 and the voltages and components associated with pins 1, 2, 4, 7 and 9 of IC U201. If sound is now present, check the voltages and components associated with pins 10, 11, 12, 14, 15 and 16 of IC U201. Also check the Sound Take-Off Transformer (T301).

U201:
1 - 25.3v
2 - 12.3v
3 - GND
4 - GND
5 - GND
6 - N/C
7 - 2.05v
8 - GND
9 - 8.84v
10 - 4.12v
11 - 4.12v
12 - 6.14v
13 - GND
14 - 4.23v
15 - 4.23v
16 - 6.34v

Let me know if you need the audio chunk of the schematic.