4. TROUBLE SHOOTING
- 89 -
4.7.4 Checking PAM Block
TP1. GSM_PA_RAMP : Power Amp Gain Control. typically, 0.2V < Vramp < 1.6V
TP2. GSM_PA_EN : Power Amp Enable
(Power ON : higher than 1.25V , Power OFF : lower than 0.4V)
TP3. GSM_PA_BAND : Power Amp Band Selection Control
(GSM Mode : -0.2V < VBS < 0.4V , DCS/PCS Mode : 1.25V < VBS < 3.0V)
TP4. +VPWR : PAM Supply Voltage Vcc higher than 3.0V
Schematic of GSM PAM Block
TP1
TP2
TP3
TP4
Rev.D
EGSM
C136
0.01u
10nH
L116
100p
C438
4
p
1.5nH
L403
100ohm
100ohm
R113
R117
100ohm
R107
C153
15p
EFC
FL1
C123
0.01u
68p
C139
C134
0.01u
GND3
9
GND4
10
GND5
GND6
12
GND7
13
GND8
14
GND9
16
21
P_GND
19
RSVD_GND
VAPC
20
17
VBATT
2
VCC1A
6
VCC1B
BS
1
DCS_PCS_IN
3
15
DCS_PCS_OUT
EGSM_IN
4
EGSM_OUT
11
ENABLE
18
GND1
5
GND2
7
8
SKY77318
U101
C149
15p
C121
33u
C138
NA
+VPWR
GSM_PA_BAND
GSM_PA_EN
GSM_PA_RAMP
TP2
TP4
TP3
TP1
Summary of Contents for U250
Page 1: ...Date June 2007 Issue 1 0 Service Manual Model U250 KU250 Service Manual U250 KU250 ...
Page 3: ... 4 ...
Page 20: ...3 TECHNICAL BRIEF 21 Fig 1 2 RTR6275 RX feature ...
Page 28: ...3 TECHNICAL BRIEF 29 Figure1 7 PM6650 Block Diagram ...
Page 41: ...3 TECHNICAL BRIEF 42 Table 1 2 Description of RF configurations ...
Page 45: ...3 TECHNICAL BRIEF 46 Figure 1 12 PM6650 Functional Block Diagram ...
Page 72: ...4 TROUBLE SHOOTING 73 4 1 RF Component 4 TROUBLE SHOOTING LGMC ...
Page 73: ...4 TROUBLE SHOOTING 74 Block Diagram Block Ref Name UMTS Part Name Function Comment ...
Page 77: ...4 TROUBLE SHOOTING 78 Check C312 of PMIC U300 Check R213 of MSM U201 T ...
Page 81: ...4 TROUBLE SHOOTING 82 ...
Page 84: ...4 TROUBLE SHOOTING 85 ...
Page 85: ...4 TROUBLE SHOOTING 86 4 7 Checking GSM Block 1 3 2 ...
Page 87: ...4 7 3 Checking RF Tx level 4 TROUBLE SHOOTING 88 ...
Page 90: ...4 TROUBLE SHOOTING 91 ...
Page 97: ...4 TROUBLE SHOOTING 98 R313 Q301 Q302 Q300 Charging part Main PCB Front ...
Page 107: ...4 TROUBLE SHOOTING 108 R422 R421 U401 ...
Page 109: ...4 TROUBLE SHOOTING 110 C401 C402 R406 C407 CN401 ...
Page 111: ...4 TROUBLE SHOOTING 112 Analog Switch Audio Amp SPK ...
Page 113: ...4 TROUBLE SHOOTING 114 MIC400 C417 R424 ...
Page 115: ...4 TROUBLE SHOOTING 116 Ear_Sense_N MIC Input ...
Page 117: ...4 TROUBLE SHOOTING 118 VPWR MOTOR_PWR ...
Page 134: ...6 BLOCK DIAGRAM 135 Table 2 1 RF Block Component ...
Page 136: ...6 BLOCK DIAGRAM 137 6 2 2 Memory Interface Fig 2 3 Memory Interface Diagram ADDRESS 14 0 ...
Page 137: ...6 BLOCK DIAGRAM 138 6 2 3 USB UART SIM JTAG Interface Fig 2 4 USB UART SIM JTAG Interface ...
Page 139: ...6 BLOCK DIAGRAM 140 6 2 4 Placement Top Side LGMC ...
Page 140: ...6 BLOCK DIAGRAM 141 Bottom Side LGMC ...
Page 141: ... 142 ...
Page 146: ... 147 LGMC 8 PCB LAYOUT U250 KU250 ...
Page 147: ... 148 LGMC 8 PCB LAYOUT U250 KU250 ...
Page 157: ... 158 ...
Page 174: ...Note ...
Page 175: ...Note ...