LG NP7550 - LGV490 Mobile Disassembly

3-8
ELECTRICAL TROUBLESHOOTING GUIDE
2. CHARGING BATTERY
Charging battery.
Connect CN900, CN301.
Connect CN901.
Change adapter.
Replace IC300.
Change battery.
Charging.
Connect adapter cable.
Does 9.6 V come out
CN301 pin11, 12, 13?
Replace IC902.
Does 9.6 V enter IC906
(Check pin2, 3)?
IC906 is HIGH
(Check pin9)?
Red LED of
power key blink?
Check the connection
of adapter cable.
NO
YES
YES
NO
NO
NO
If it still doesn’t work
NO
Check connection
of CN900 and CN301.
Does 5 V come out
CN300 pin1?
Check
connection of CN901.
YES
NO
YES
NO
YES
YES
YES
NO