LG MG810c Service Manual page 49

4. TROUBLE SHOOTING
E. SIM Detect Trouble Shooting
SIM interface scheme is shown below.
SIM_IO, SIM_CLK, SIM_RST ports are used to communicate DBB with ABB and the Charge Pump in
ABB enables 1.8V/3V SIM operation.
SIM_CLK : SIM Card reference clock
SIM_RST : SIM Card async/sync reset
SIM_IO : SIM Card bi-directional data line
• Connection between SIM and DBB
- SIM_CLK, SIM_IO, SIM_RST
• Check Points
- Contact between SIM and socket
- Soldering of SIM socket
• Trouble Shooting
- Insert the SIM into socket
- Connect PIF_UNION Jig to the phone, and Power on
SIM I/O CKTs
V_SIM
CN203
GND VCC
VPP RST
SIM_IO I_O CLK
22p C224
C223 0.1u
SIM_PWCTRL : SIM Card power activation
SIM_RnW : SIM Card data line direction
SIM_CD : SIM Card presence detection
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V_SIM
SIM_RST
SIM_CLK
C225 C226 C227
1u 150p 150p