SAMSUNG Proprietary-Contents may change without notice
5-3
SGH-A400 Flow Chart of Troubleshooting and Circuit Diagram
5-3 SGH-A400 Sim Part
Phone can’t access SIM card
Y
N
Y
Check the pin 1, 5 of
CN400. voltage is 2.8V ?
Check the SIM related circuit of the U400
N
Y
Check the SIM
connector’s CN400
Connection to
SIM card
Resolder CN400
END
Y
Check the circuit around U515
(Serial EEPROM) and data stored in it
VSYN
VCCD
Sim_Dat
Sim_En
Sim_Reset
VRF
VOsc
VCCA1
PMIC_RESET
C410
150PF
100
R410
Clk_Rqst
S_Dat
S_Clk
Sim_Clk
CN400
1
1
U400
VCCD
VTIC
VSIM
VSW1
24
25
VSW2
VCCD
ISENP
100K
R404
ZD402
R407
4.7K
VBAT
10
G
ISENN
VCCD
R409
3
2
1
VSIM
U8016-1
4
1
2
8
7
4.7K
VOUT_1A
30
VOUT_2
VOUT_3
28
31
VOUT_4A
VOUT_4B
32
29
VOUT_5
VOUT_6
27
43
VOUT_7
VOUT_8
48
VREF_CAP
44
VSUB_P
20
17
18
SIM_CLK_M46
SIM_DA
T
A_CARD
15
SIM_DA
T
A_M46
16
14
SIM_ENABLE
21
SIM_RST_CARD
SIM_RST_M46
22
VBAT1
37
38
VBAT2
VBOOST
39
VOUT1B
34
33
35
NC1
NC2
36
NC3
4
NC4
26
9
PMIC_INTERRUPT
45
POWER_KEY
POWER_ON_RESET
11
RESET_B
2
3
RSS_CLOCK
RSS_DATA
1
SIM_CLK_CARD
6
7
ENABLE_2
ENABLE_3
8
GND1
23
12
GND2
5
GND3
49
GND4
GND5
50
51
GND6
GND7
52
GND_SENSE
19
ALARM_IN
46
13
BOOST_ENABLE
42
BOOST_PULSE
41
BOOT_SENSE
BOOT_VDD
40
10
CLOCK_REQUEST
47
DTR_IN
ENABLE_1
2 2
3
3
4
4
5
5
6
6
G
7 8
G G
9