WCDMA transmitter troubleshooting flowchart
WLAN RF troubleshooting
Introduction to WLAN RF troubleshooting
• Most RF semiconductors are static discharge sensitive. ESD protection must be taken care of
during repair (ground straps and ESD soldering irons).
• N6300 and N6301 are moisture sensitive so parts must be pre-baked prior to soldering. In
addition to key components described in this section, there are a lot of discrete components
(resistors, inductors and capacitors) for which troubleshooting is done by checking if soldering
of the component is done properly (for factory repairs checking if it is missing from PWB).
The WLAN RF section mainly consists of the WLAN ASIC STLC4560 (N6300), the Front End Module, FEM (N6301),
the 2.4GHz filter (Z6300), the antenna diplexer (Z6650) and the WLAN antenna embedded in the battery cover.
The WLAN troubleshooting is divided into two major sections: radiated and conducted testing. Radiated
testing is further divided into two parts.
The conducted testing is to identify problems that may be caused by WLAN circuits on the phone PWB. See
the General WLAN RF troubleshooting flowchart. This test also has two sub-tests: the WLAN front-end test
and the WLAN ASIC test. The WLAN autotune is performed if either the FEM or the WLAN ASIC is replaced with
a new one.
All RF measurements should be done using a spectrum analyzer and TX power is measured in channel power,
dBm/22MHz. An oscilloscope with a 10:1 probe is used for DC-voltages and low frequency signals
measurements. Short circuits on capacitors and resistor values can be verified with an ohmmeter.
Copyright © 2008 Nokia. All rights reserved.
Page 4 –19