Gsm Transmit - Samsung SGH-N188 Service Manual

Dual band mobile cellular phone
Table of Contents

Advertisement

5-12 GSM Transmit

Flow chart of trouble shooting
Tx On (level : 5)
U208
Yes
Pin 2
30 dBm
No
U208
Yes
Pin 7
30 dBm
No
U206
Yes
Pin 4
30 dBm
No
U106
Yes
Pin 9
-10 dBm
No
U200
Resolder of Change
Yes
C217, R211, R212,
Pin 6
-10 dBm
No
U200
Pin 7
0.5V
Yes
Pin 5
2.8 V
Pin 3 = 0.5~2.5V
Yes
At 540MHz,
No
U104
-10 dBm
At CH - 270MHz,
U107
-10 dBm
Yes
U201
No
Pin 13, 14, 15, 16
40 mV
Yes
Check U201
No
Pin 46
2.5 V
U201 (Pin35, Pin46)
Pin 35
0.5 V
Yes
Resolder
U414
Resolder
J401 pin 20
Check
Yes
VC1 : H
VC2 : L
VC3 : L
No
Resolder
U206, C264
Check
U106 : +VBATT
Pin 10 (APC)
OK?
No
R210, C121
Resolder or Change
U200, R201
Resolder
U201, U104, U107
Resolder
OneC(U414)
Resolder
Change or Resolder
U208
Check
Ant. S/W, Control Circuit
Yes
Resolder or
Change U106
Check +VBATT
or APC Control
5-12

Advertisement

Table of Contents
loading

Table of Contents