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Flow Chart of Troubleshooting
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9-6
9-1-3. Sim Part
Phone can't access SIM Card
YES
Check the pin 1 of
SIM300 Voltage = 3V
NO
Check the circuit related to
U300
YES
Check the SIM
connector's to SIM card
NO
Resolder or change
SIM300
NO
Check the related circuit of
SIM300
YES
Check the related circuit of SIM300
YES
NO
Check the related circuit of
U300
Check the circuit around U300 output and
voltage supply circuitry
YES
END
7
7
8 8
9 9
13
G
G
14
15
G
G
16
10 10
11
11
12 12
2 2
3
3
4
4
5 5
6
6
SIM300
1
1
C302
C303
C300
00
3
R
V
C301
10
3
R
V
C304
20
3
R
V
30
3
R
V
SIM_RST
VSIM_3.0V
SIM_IO
SIM_CLK