Nokia 2650 - Troubleshooting Chart for GSM900 Transmitter

RH-53/54
Nokia Customer Care
54 COMPANY CONFIDENTIAL 2005
Copyright © 2005 Nokia. All Rights Reserved.
Measure the output power of the phone; it should be around 32.5 dBm for low band and 29.5
dBm for highband. Remember the loss in the jig; around 0 dB for the low band and 0.1 dB for
the high band.
Troubleshooting chart for GSM900 transmitter
For the spectrum analyzer measurements in the following chart use the 500ohm passive probe
giving an approximately 20 dB lower reading than indicate in the following figures. Since the
signal measured is bursted it is advised to set the analyzer to maxhold.
Figure 44:Troubleshooting chart for GSM900 transmitter
Signal ok on
GSM tester
Power
laccording to
level
Check channels
and bands
TX Power
tuning working
Check frequency,
TXC, PLL, Vdet, I/
Q
Check I/Q
SPA Burst
Power
Check PA input
power
Output power
Mjoelner
Check DC
signals
Signal ok on
GSM tester
Change FEM
Check I/Q, PLL,
TXC, DC
Z603/R714
(T600/R711)
Change FEM
(N700)
Change FEM,
loop, Z603/T600
Yes Yes
NoNo
No
No
No
Yes
Yes Yes
No
Yes
No
No
Yes
Yes