LG NP8540 Service Manual page 42

ELECTRICAL TROUBLESHOOTING GUIDE
4. AUDIO (Wi-Fi MODE)
AMP
Is the Vcc of IC700 18 V?
(Pin6, 43)
Is the Vdd of IC700 3.3 V?
(Pin30)
① Check mode (Wi-Fi, B/T, Portable)
Check AMP I2S signal
(IC700 Pin23, 24, 25).
Check PWM signal
(IC700 Pin2, 4, 45, 47).
Check Audio signal
(CN700).
OK
YES
YES
YES
YES
YES
YES
YES
NO
Check power circuit troubleshooting.
NO
Check power circuit troubleshooting.
NO
NO
NO
Check L701, L702
and speaker cable connection.
3-19
Replace IC700.
Replace IC700.