LG SNC4R - Page 49

3-20
Copyright © 2021 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
VCC33 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 R308 Voltage 3.3 VA
Replace Main PCB
Replace Main PCB
YES
YES
NO
NO
Check FB313 Voltage 3.3 V
Replace Main PCB
YES
NO
OK
ADAPTER POWER CIRCUIT