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Flow Chart of Troubleshooting
3-12
3-2. RF
3-2-1. GSM Rx
Normal condition
catch the channel ?
Check PAM400
pin 12
≥
-65
dbm ?
Check U400
pin 21,22
≥
-
65dBm ?
Yes
No
No
Check PAM400
pin 16
≥
-65 dbm
?
Yes
No
Yes
Check ANT,
C303, R300
Resolder or change
RFS400, L300, L301, L303, C305, C302
Resolder or change
PAM400
Resolder or change
F401, C319, U409, L306
Resolder or change
UCP201
CONTINOUS RX ON
RF INPUT : 62CH
AMP : -50dbm
Check U400
pin 13 = 2.9V
Yes
Resolder or change
UCP101
Yes
No
No
1
2
3
4
5