Nokia 2650 - Page 202

Issue 2 06/2005 COMPANY CONFIDENTIAL 45
Copyright © 2005 Nokia. All Rights Reserved.
RH-53/54
Nokia Customer Care
Figure 35:Troubleshooting chart for GSM900 receiver
Osciloskope at
RX I/Q.
Signal 588mVpp
DC offset 1.35V
Freq. 67.71kHz
Apply -55dBm
942.4 MHz
Offset 67.71kHz
from generator to
antenna pad
GSM1800 OK
Check RX/TX
switch at RX900
Z700
-56 dBm
Osciloskope
check VC1 and VC2 at
Z700
Signal=0Vdc
Check Mjoelner
N600
Spectrum analyser
SAW filter Z602 output
-65dBm
Check Z602
Spectrum analyser
Cehck signal after inductors
L602 and L603
-65dBm
Osciloskope
VRX 2.7 Vdc
Check Mjoelner serial
interface
Check inductor
L602, L603
Check Baseband
Yes
No
No
Yes
No
No
Yes
No
No
Yes
Yes
Check RX/TX
switch
Z700
Yes