Flow Chart of Troubleshooting
3-20
3-2. RF
3-2-1. GSM850 Receiver
CONTINUOS RX ON
RF INPUT : 190CH
Cell power : -50dBm
NORMAL CONDITION
catch the channel?
CHECK
C104
NO
1
YES
F100 CHECK
pin6
≥
-65dBm?
RFS100
resolder or change
2
NO
YES
F101 CHECK
pin18,19
≥
-
F100
resolder or change
NO
3
U104 CHECK
pin2,3
≥
-65dBm?
YES
L103, L104, C109
resolder or change
NO
4
YES
check battery contact
NO
the power source
of U104
5
6
YES
check OSC100
and
change
U104 CHECK
Pin15,17
:13MHz
NO
YES
END
GSM Receiver is ok?
GSM RX path component
resolder or change
NO