Step 1. Local Oscillator Checking; Fig 26 Fault Finding Chart - Nokia RH-13 Series Troubleshooting Manual

CCS Technical Documentation
Apply signal to ext.
antenna connector
f= 1960.029 MHz ch
unmodulate
level= -50 dBm
Check signal level
at RX I/Q J808,
J809, J818, J819
Check signal level
at diplexer Z908
Check signal level
at duplex filter
Z962 input
Check signal level
atLNA V804 input
C heck signal level
at R X band filter
Z 802 input
C heck signal level
at mix1_B input
C ontinue
troubleshooting as
A MPS/T D MA 800

Step 1. Local oscillator checking

Carrying out this step VCO signal of 1st and 2nd mixers can be checked. 2nd mixer RX
VHF VCO frequency is constant 268.08 MHz but for the 1st mixer UHF VCO frequency
depends on the channel. The UHF VCO frequencies for the 1st mixer are:
Issue 1 11/02
Fault finding chart.
Figure 26:
1000)
OK
Not OK
Not OK
input
OK
Not OK
OK
Not OK
OK
Not O K
O K
Not O K
O K
in
ãNokia Corporation
TDMA1900 RX is
OK
Replace external
antenna connector
X900
Replace diplexer
Z908
Replace duplex
filter Z962
C heck components
around lna and
measure supply
voltages
R eplace R X band
filter Z 802
RH-13
Troubleshooting
Page 43