LG F1200 Service Manual page 58

(10) SIM Detect Trouble
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_RST
SIM_CLK
SIM_IO
SIM_CLK : SIM Card reference clock
SIM_RST : SIM Card async/sync reset
SIM_IO : SIM Card bi-directional data line
detection
• Connection between SIM and DBB
- SIM_CLK, SIM_IO, SIM_RST
• Check Points
- Contact between SIM and socket
- Soldering of SIM socket
C419 C418 C417
150p 150p 22p
SIM_PWCTRL : SIM Card power activation
SIM_RnW : SIM Card data line direction
SIM_CD : SIM Card presence
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4. TROUBLE SHOOTING
J400
1 4
VCC GND1
2 5
RST VPP
3 6
CLK IO
7 10
GND2 GND5
8 9
GND3 GND4