1.2 No Sound
1) Main board
1. Check that the PC/AV switching signal is correct.
Pins 10 and 11 of IC5001...................AV : L, PC : H
2. Check that audio signal is observed at following points.
Pins 11-12(PC)/13-14(AV) of K10B/K50B
3. Check that the MUTE signal is correct.
Pin 5 of K5A .......................................Mute-On: H
4. Check that the MUTE signal is correct.
Pin 12 of IC1803 ................................Mute-On: L
5. Check that the PC/AV switching signal is correct.
Pin 16 of IC1804 ................................AV : L, PC : H
2) Audio board
1. Check that sound volume control signal is correct.
Pin 4 of IC001
2. Check that audio signal is observed at pin 2 of IC001.
3. Check the MUTE signal at pin 3 of IC001.
Pin 3 of IC001 ....................................Mute-On: H
4. Check that Vcc-voltage(+12V) is applied at pins 1 and 9 of IC001.
Part 4: Troubleshooting
4-6
Fig. 4-2
