3. TROUBLE SHOOTING
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3.5.2.1 Checking GSM PAM DC Power Circuit
4. Trouble Shooting
4. 5. GSM RF Part
4 5 2 GSM850/900/1800/1900 Tx
4. 5. 2. GSM850/900/1800/1900 Tx
4. 5. 2. 1.
Checking GSM PAM DC Power Circuit
Test Point
TP1
TP3
TP4
U1300
TP2
TP2(1328)
TP3(R1302)
Circuit Diagram
TP4(R1303)
TP1(C1318)
26
1n
C1330
+VPA0
C1328
10
u
2G
3/4G
RFOUT_GSM_HB
RFIN_B26
RFIN_B5_B8
GND1
VIO
GND13
RFIN_B1_B2
RFIN_GSM_HB
GND7
GND6
RFIN_GSM_LB
VBATT
GND3
SCLK
GND8
RFIN_B4
GND5
GND9
GND1
1
GND10
GND2
GND4
SDATA
RFOUT_GSM_LB
GND12
RFOUT_B4
RFOUT_B2
RFOUT_B5_B26
GND14
RFOUT_B8
VCC1
VCC2
VCC_GSM
RFOUT_B3
GND15
RFOUT_B1
GND16
NC
GND17
GND18
GND19
GND20
PGND
U1300
SKY77629-21
43
42
41
40
39
37
38
35
36
34
26
27
28
29
30
31
32
33
23
22
9
12
7
20
21
19
15
2
18
8
10
11
14
16
17
13
1
25
6
5
4
3
24
+1V8_VREG_L10
+VPA_BATT0
C1318
1n
C1319
10u
R1302
0
2
1
R1303
0
GND
GND
RFFE1_CLK
RFFE1_DATA
TP2(1328)
TP3(R1302)
TP4(R1303)
TP1(C1318)