Sim Detect Troubleshooting - LG L704I Service Manual

4.9 SIM Detect Troubleshooting

USIM Initial sequence of L704i is :
USIM_CLK,USIM_RST,USIM_DATA triggered → VREG_USIM_2.85V go to 2.85V → USIM IF work
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Only for training and service purposes
Start
Re-insert the SIM card
Work well?
No
VREG_USIM_2.85V is 2.85V?
USIM_P_CLK is run?
YES
Change SIM card
Work well?
No
Change the Main board
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4. TROUBLE SHOOTING
Yes
End
NO
Check J1
Yes
End
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