User Guide

PAMS
Technical Documentation
NSE–8/9
Troubleshooting
Page 28
Issue 1 07/99
2.3. Fault finding chart for GSM receiver
Oscilloscope
SUMMA N700 pin 41 VREF Vdc = 1.5 Volt
SUMMA N700 pin 35 VRX_2 Vdc = 2.8 Volt
CRFU3 N600 pin 8, 47 VSYN_2 Vdc = 2.8 Volt
CRFU3 N600 pin 13, 33 VRX_1 Vdc = 2.8 Volt
NO
YES
Spectrum analyser
Verify 500 ohm passive probe
Measure at Diplexer (Z503)
antenna port
947 MHz
Pin = –50 dBm
Check
Spectrum analyser,
probe and signal
generator
NO
OK
Spectrum analyser
CRFU3 N600 pin 27
947 MHz
Pin = –54 dBm
Spectrum analyser
CRFU3 N600 pin 23
947 MHz
Pout = –35 dBm
Check
Diplexer (Z503)
Duplexer (Z500)
Check
CRFU3 (N600)
pin 24, BandSelect
pin 28, FraCtrl
YES
Check
BaseBand
YES
YES
NO
NO
.
.