Nokia NHL-10 - Page 16

NHL-10
CCS Technical Documentation RF Troubleshooting
16 COMPANY CONFIDENTIAL ISSUE 2 01/2004
Copyright © 2003 Nokia. All Rights Reserved.
The input freq/level of signal generator is 1960.067710MHz, -60dBm
Figure 7: Fault finding chart for GSM1900
Apply -60 dBm
1960 MHz, offset
67.71 kHz
from generator to
antenna connector
Check RSSI using
Phoenix Does it
match Sig Gen
Output level ?
Is L.O running ?
Check RX/TX
switch at RX 1900
Z601
Input -63 dBm
Output -65 dBm
Oscilloscope
check Vc1, Vc2,
Vc3 at Z601 signal
Vc1, Vc3 =0V
Vc2=2.7V
Spectrum analyzer
EGSM SAW filter
Z603
output -70 dBm
Spectrum analyzer
Check signal after
inductors L608 and
L609
-73 dBm
Check SAW filter
Z603
Oscilloscope
VRX 2.7 V on
Mjoelner
Check inductors
L608, L609
Check Base band
Check RX/TX
switch
Check Mjoelner
YES
YES
NO
NO NO
NO
NO
NO
YES
YES
EGSM chain
functional
Refer to
Synthesiser Fault -
finding chart
Probe J606 -609
RX I &Q Does
waveform look like
example given
earlier ?
Probe J211 &J212
Is digital data
visable ?
Replace UPP
Replace UEM
YES
YES
NO
YES
YES
NO
NO
visible