Dcs Transmitter - Samsung SGH-R200 Service Manual

5-14 DCS Transmitter

Flow Chart of Troubleshooting and Circuit Diagrams
Tx On (level : 0)
U401
Yes
Pin 8
25 dBm
No
U401
Yes
Pin 3
25 dBm
No
U402
Yes
Pin 3
25 dBm
No
U404
Pin 8
-10 dBm
No
U302
Yes
Pin 10
-10 dBm
No
U302
No
Pin 7 2.5 V
Pin 5 2.5 V
Pin 3 = 0.5~2.5 V
Yes
No
U301
pin 30, 47 -10 dBm
Yes
U301
No
Pin 17, 18, 19, 20
40 mV
Yes
Check U301
No
Pin 38, Pin 35
2.5 V
Yes
Resolder
U110
Resolder
J401
Check
VC1 : H
VC2 : L
No
Resolder
U402, C402
Check
Yes
U404 : +VBATT,
Pin 2 (APC)
OK?
Resolder or Change
C334, R410, R413, R414, C418
Resolder
U302, R314
Resolder
U301, U304
Resolder
OneC(U110)
Resolder
U301 (Pin35, Pin38)
Yes
Change or Resolder
U401
Check
Ant. S/W Control Circuit
Yes
Resolder or Change
U404
No
Check +VBATT
or APC Control
5-23