LG KM710 Service Manual page 59

4. Trouble Shooting
START
Check is the CN700(main key)
Is well-soldered?
YES
R712(main key)
Is well-soldered?
YES
Check is the connection of
Main key, Main, Main FPCB ?
YES
Check the Main FPCB
Main FPCB is OK?
YES
U103( Main) check ?
YES
Booting is operating properly
LGE Internal Use Only
Re-solder the CN700
(main battery terminal)
NO
Re-solder
R712(main power key)
NO
Connect the Main key, Main, Main FPCB
NO
Replace Main FPCB
NO
Replace the U103(Main)
NO
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