Dcs Transmit - Samsung SGH-A200 Service Manual

5-14 DCS Transmit

Flow chart of Troubleshooting and Circuit Diagram
Tx On (level : 0)
U304
Yes
Pin 2
≥ 25 dBm
No
U304
Yes
Pin 13
≥ 25 dBm
No
U312
Yes
Pin 5
≥ 25 dBm
No
U312
Pin 8
≥ 0 dBm
No
U200
Yes
Pin 10
≥ 10 dBm
No
U200
No
Pin 7 ≥ 2.5 V
Pin 5 ≥ 2.8 V
Pin 3 = 0.5~2.5 V
Yes
U305
No
pin 30, 47
≥
-10 dBm
Yes
U305
No
Pin 17, 18, 19, 20
≥ 40 mV
Yes
No
Check U305
Pin 38, Pin 35
≥ 2.5 V
Yes
Resolder
U108
Resolder
J301
Check
VC1 : L
VC2 : H
VC3 : L
No
Resolder
U318, C364
Check
Yes
U312 : +VBATT
Pin 2 (APC)
OK?
Resolder or Change
C697, C346, R365, R363
Resolder
U108, U457, U200
Resolder U302
Resolder
OneC(U108)
Resolder
U305 (Pin35, Pin38)
Yes
Change or Resolder
U304
Check
Ant. S/W, Control Circuit
Yes
Resolder or Change
U312
No
Check +VBATT
or APC Control
5-21