Gsm Receiver - Samsung SGH-Q208 Service Manual

5-11. GSM Receiver

RX On
RF input : 62 CH
Amp. : -50 dBm
U1006
Pin 9
-70 dBm
U1006
Pin 5
-70 dBm
F1004
pin 5
-73 dBm
U901
pin 4
&
F901
pin 4
-60 dBm
F902
pin 1, 2
-55 dBm
F902
pin 5, 6
-60 dBm
U901
pin 43, 44
-50 dBm
END
Y
Y
N
Y
Y
-55 dBm
2.5 Vdc
Y
Y
N
Y
Y
N
Y
SAMSUNG Proprietary-Contents may change without notice
SGH-Q208 Flow Chart of Troubleshooting and Circuit Diagrams
•All or RF values by dBm should be measured in max hold status of
RF spectrum analyzer in active call
Resolder or Change CN1001
N
Resolder U1006,
Pin 5 -70 dBm?
Y
Resolder F1004
N
Resolder or Change U901
N
Resolder or Change F901
N
Check OSC901
pin 1 -20 dBm
Y
N
Check OSC902
pin 1 -20 dBm
Y
5-11
Check voltage
U1006 pins
Pin 2 : L
N
Pin 4 : H
Pin 8 : H
Pin 10 : L
Change OSC901
N
Resolder or
Change U901
Change F902
Resolder or change
N OSC902
Change U901