Nokia Mobile Phones NSE-5 Series Service Manual page 250

NSE–5
Troubleshooting
Fault finding chart for GSM receiver
Oscilloscope
SUMMA N700 pin 41
SUMMA N700 pin 35
CRFU3 N600 pin 8, 47
CRFU3 N600 pin 13, 33 VRX_1
Spectrum analyser
Verify 500 ohm passive
probe
Measure between Me-
chanical Switch (X501)
and Diplexer (Z503),
Pin = –50 dBm, 947
MHz
Spectrum analyser
CRFU3 N600 pin 27
Pin = –55 dBm, 947
MHz
Spectrum analyser
CRFU3 N600 pin 23
Pout = –33 dBm, 947
MHz
Spectrum analyser
CRFU3 N600 pin 18,19
Pin = –48 dBm, 947
MHz
Page 24
VREF Vdc = 1.5 Volt
VRX_2 Vdc = 2.8 Volt
VSYN_2 Vdc = 2.8 Volt
Vdc = 2.8 Volt
Yes
Yes
Yes
Yes
PAMS
Technical Documentation
Check
No BaseBand
Check
No Spectrum analys-
er, probe and sig-
nal generator
Check
Diplexer (Z503)
No Duplexer (Z500)
Check
CRFU3 (N600)
No pin 24, BandSelect
pin 28, FraCtrl
Check
No GSM Filter (Z600)
Issue 1 07/99