3-18
Copyright © 2019 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
Tuner is not 3.3 V
Check F301 Voltage 25 VA
Check FB305 Voltage 5.1 VA
Check Adapter
Replace Main PCB
YES
YES
YES
NO
NO
Check FB304 Voltage 12 VA
Check R311 Voltage 3.3 V
Replace Main PCB
Replace Main PCB
YES
YES
NO
NO
OK
ADAPTER POWER CIRCUIT