Nokia 2600 服务手册
ISSUE 1 09/2004
COMPANY CONFIDENTIAL
19
Copyright © 2004 Nokia. All Rights Reserved.
RH-59/60
Nokia Customer Care
General RF Troubleshooting
Two types of measurements are used in the following. It will be specified if the measurement
type is "RF" or "LF".
type is "RF" or "LF".
•
• RF measurements are done with a Spectrum Analyser and a high-frequency 500
ohm passive probe, for example HP54006A. (Note that when measuring with the
500 ohm probe the signal will be around 20 dB attenuated. The values in the follow-
ing will have these 20 dB subtracted and represent the real value seen on the spec-
trum analyser).
500 ohm probe the signal will be around 20 dB attenuated. The values in the follow-
ing will have these 20 dB subtracted and represent the real value seen on the spec-
trum analyser).
Note that the testjig have some losses which must be taken into consideration when calibrating
the test system.
the test system.
•
• LF (Low frequency) and DC measurements should be done with a 10:1 probe
and an oscilloscope. The probe used in the following is 10MW/8pF passive probe.
If using another probe then bear in mind that the voltages displayed may be slightly
different.
If using another probe then bear in mind that the voltages displayed may be slightly
different.
Always make sure the measurement set-up is calibrated when measuring RF parameters on
the antenna pad. Remember to include the loss in the module repair jig when realigning the
phone.
the antenna pad. Remember to include the loss in the module repair jig when realigning the
phone.
Most RF semiconductors are static discharge sensitive.
So ESD protection must be ap-
plied during repair (ground straps and ESD soldering irons). Mjoelner and Bifrost is moisture
sensitive so parts must be pre-baked prior to soldering.
sensitive so parts must be pre-baked prior to soldering.
Apart from key-components described in this document 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 and checking if the component is missing from PWB. Ca-
pacitors can be checked for short-circuiting and resistors for value by means of an ohmmeter,
but be aware in-circuit measurements should be evaluated carefully.
(resistors, inductors and capacitors) for which troubleshooting is done by checking if soldering
of the component is done properly and checking if the component is missing from PWB. Ca-
pacitors can be checked for short-circuiting and resistors for value by means of an ohmmeter,
but be aware in-circuit measurements should be evaluated carefully.
In the following both the name EGSM and GSM850 will be used for the lower band and both
PCN and GSM1900 will be used for the upper band.
PCN and GSM1900 will be used for the upper band.