User Guide

5-19 Flow chart of trouble shooting and Circuit Diagram
5-12 GSM Transmit
Tx On (level : 5)
U304
Pin 2
≥ 30 dBm
U304
Pin 7
≥ 30 dBm
U312
Pin 4
≥ 30 dBm
U312
Pin 1
≥ 0 dBm
Resolder
J301
Check
VC1 : H
VC2 : L
VC3 : L
Change or Resolder
U304
Resolder
U318, C353
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Check
Ant. S/W, Control Circuit
Check
U312 : +VBATT
Pin 2 (APC)
OK?
Resolder or
Change U312
Yes
Check +VBATT
or APC Control
No
U200
Pin 6
≥ 7 dBm
Resolder or Change
C698, R335, R364, R366
No
Yes
U200
Pin 7 ≤ 0.5 V
Pin 5 ≥ 2.8 V
Pin 3 = 0.5~2.5 V
Resolder
U108, U457, U200
U305
pin 30, 47
≥ -10 dBm
Resolder
U302
U305
Pin 17, 18, 19, 20
≥ 40 mV
Resolder
OneC(U108)
Check U305
Pin 38 ≥ 2.5 V
Pin 35 ≤ 0.5 V
Resolder
U305 (Pin35, Pin38)
Resolder
U108
No
No
No
No
Yes
Yes
Yes
Yes