4. TROUBLE SHOOTING

4.4 USIM Detect Troubleshooting

USIM Initial sequence is :

VREG_USIM_2.85V go to 1.8V or 3.0V Æ USIM_CLK,USIM_RST,USIM_DATA triggered Æ USIM IF work

START

Re-insert the SIM card

Work well ?

No

TP1(Vreg_USIM) is 1.8V or 3.0V ? TP2(USIM_CLK) & TP3(RST) is run ?

Yes

Change the SIM card

Work well ?

Yes

END

Yes

END

No

Check J301

Work well ?

Yes

 

No

 

No

 

Change the Main board

 

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LG Electronics LG-C320 service manual Usim Detect Troubleshooting, Re-insert the SIM card Work well ?, Check J301