Sim Detect Trouble - LG U300 Service Manual

4. TROUBLE SHOOTING

4.10 SIM Detect Trouble

USB Initial sequence of U300 is :
VREG_USIM_2.85V(C433 of PM6650-2) go to 3.0V → USIM_CLK,USIM_RST,USIM_DATA triggered
→ USIM IF work(Schematic and place are refer to SIM technical brief)
VREG_USIM_2.85V
(J300 Pin 1)
Start
Re-insert the SIM card
Yes
Work well?
No
NO
VREG_USIM_2.85V is 3.0V?
USIM_P_CLK is run?
YES
Change SIM card
Yes
Work well?
No
Change the Main board
- 100 -
End
Check J300,
VREG_USIM_2.85V
End
USIM_P_RST
(J300 Pin 2)
USIM_P_CLK
(J300 Pin 3)
USIM_P_DATA
(J300 Pin 6)