Rf Key Component Placement - Nokia NEM-4 Series Troubleshooting Instructions

NEM-4
RF Troubleshooting
Rx calibration done via Phoenix software is temperature sensitive because of cali-
bration of 26 MHz reference oscillator (VCXO). According to Mjoelner specification
ambient temperature has to be in a range from 22°C to 36°C.
Apart from key-components described in this document there are a lot of discrete com-
ponents (resistors, inductors and capacitors) for which Troubleshooting is done by check-
ing if soldering of the component is done properly and checking if the component is
missing from PWB. Capacitors can be checked for short-circuiting and resistors for value
by means of an ohm-meter, but be aware in-circuit measurements should be evaluated
carefully.
In the following both, the name EGSM and EGSM900 will be used for the low band. DCS
or PCN and GSM1800 will be used for the mid band. PCS and GSM1900 will be used for
the high band.

RF Key component placement

Page 6(b)-54
Company Confidential
Figure 1: RF key component placement
Copyright  2003 Nokia Corporation
Company Confidential
CCS Technical Documentation
Issue 1 09/2003