User Guide

Flow chart of Troubleshooting and Circuit Diagram 5-20
5-12 GSM Receiver
Rx On
RF input : CH center freq. + 67.7 kHz
Amp. : -50 dBm
U704
Pin 8
-60 dBm
U704
Pin 10
-60 dBm
F601
Pin 3,4
-62 dBm
U600
Pin 21, 22
-62 dBm
U600
Pin 1, 2
(100 KHz)
-50 dBm
Check RF connector
-> resolder
Resolder &
U704 Pin 10
-60 dBm
Check
VC1 : L
VC2 : L
Resolder
F601
Resolder
C605, C606, L601
Check
C503 pin 23, 24
(CH-100 KHz) X 2
C510(1080MHz)
-6 dBm
Check circuit
around U503
Resolder
U600
U601
Pin 2, 3, 4, 5
40 mV
Resolder
U601
Resolder
U400
No
No
No
No
No
No No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes