LG SPH4B-W - Page 51

3-22
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ELECTRICAL TROUBLESHOOTING GUIDE
ADAPTER POWER CIRCUIT
RBOX_3V3 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 FB316 Voltage 3.3 V
Replace Main PCB
YES
NO
OK