User Guide
Table Of Contents
- 7 - RF Description & Troubleshooting
- 1. RF Description and Troubleshooting
- 2. RF Implementation in NHL-12
- 3. Introduction to RF troubleshooting
- 4. Receiver Description and Troubleshooting
- 5. Transmitter Description and Troubleshooting
- 6. Additional Information on EDGE Troubleshooting
- 7. Synthesizer Description and Troubleshooting
- BACK TO MAIN PAGE
Issue 2 10/2004 COMPANY CONFIDENTIAL 25
Copyright © 2004 Nokia. All Rights Reserved.
NHL-12
7 - RF Description & Troubleshooting Nokia Customer Care
Transmitter troubleshooting diagram
Figure 12:Transmitter troubleshooting
Yes
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No Yes
Yes No
No
Yes
Yes
Yes
No
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No
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TX Troubleshooting
Check output signal level:
+32…+33dBm@836.6MHz(GSM850)
+29…+30.5dBm@1747.8 and 1880MHz
(GSM1800&1900)
OK?
Check
all power
levels,
OK?
TX OK
Tune
TX power
levels,
OK?
TX signal found?
Check output signal
on 500MHz span
Signal found on incorrect
frequency?
Synthesizer
troubleshooting
Check with RF probe signal level on
PA input: >=0dBm
OK?
Helgo
troubleshooting
Start TX power level tuning and check tuned coefficien values:
Highest level ~0.750…0.930(GSM850); ~0.600…0.800(GSM1800&1900)
Lowest level ~0.150…0.170(GSM850); ~0.148…0.175(GSM1800&1900)
Base level ~0.125…0.145(GSM850); ~0125…0.145(GSM1800&1900)
Major differences?
Tune TX DAC values
Check control voltage with
oscilloscope:
PA Ctrl voltage >1.5V peak
OK?
Check control loop
components
OK?
Replace Helgo
PA & ant switch
troubleshooting
Replace faulty
components