Nokia 6111 RM-82, Руководство по обслуживанию, Страница: 183 / 254

Introduction to RF troubleshooting for analysis
On the following pages you will find a step-by-step troubleshooting procedure and reference measurements
at the relevant signal points. For functional descriptions, please refer to the System module section.
Note: Most test points are not accessible unless shielding cans are cut open. This must ONLY be done
by the Return analysis technicians and for analysis only!
Notes on reference measurements
• LF & DC signals are measured with Textronix 100 MHz Scope (TDS3014) and P3010 13 pF probe.
• RF signals are measured with R&S FSIQ 7 GHz Spectrum Analyzer and Agilent resistive divider probe (10
dB, 500Ω).
• Please be aware that the RF connector on service adaptor is leaking power (into air) and acts as noise
source when probing on RX chain. In 1800 band the problem is most severe while there is no external LNA
to amplify the signal above the noise level like in the 1900 band. In 900 band the leakage is not as high
due to lower frequency.
• GSM SA settings: RBW=500 kHz, VBW=500 kHz.
• Bluetooth SA settings: RBW=2 MHz, VBW=2 MHz.
• All reference measurements were made on a RM-82 phone (GSM900).
• RF loss Module Repair Jig: 900: 0.3 dB, 1800: 0.6 dB and 1900: 0.6 dB. Bluetooth is 1.8 dB.
Auto tuning
This phone can be tuned automatically.
Autotune is designed to align the phone's RF part easier and faster. It performs calibrations, tunings and
measurements of RX and TX. The results are displayed and logged in a result file, if initiated.
Hardware set up
Hardware requirements for auto tuning:
• PC (Windows 2000/NT) with GPIB card
• Power supply
• Product specific module jig
• Cables: 3 (alt.1) RF cable, 1 GPIB cable and DAU-9S
• Signal analyser (TX), signal generator (RX) and RF-splitter
or
one device including all.
Figure 102 Auto tuning concept with CMU200
RM-82
RF troubleshooting Nokia Customer Care
Issue 1 COMPANY CONFIDENTIAL Page 8 –5
Copyright © 2005 Nokia. All rights reserved.