NHL-10
Baseband Troubleshooting
CCS Technical Documentation
ISSUE 2 01/2004
COMPANY CONFIDENTIAL
27
Copyright © 2003 Nokia. All Rights Reserved.
Audio troubleshooting
Microphone
Figure 20: Internal MIC troubleshooting
START
Check Mic module and PWB
contacts. Are they OK?
Clean contacts /
replace MIC module
Set Phone Audio Routing from MIC1
(Hand Portable) to know n w orking
audio output (I.e. EAR [HP] or
HF/HFCM [Ext]). Ensure MIC Bias
[MICB1] is ON.
Is MIC Bias 2.1V non
present at R330 or at
the MIC?
Check R330, R332 and
other passive components
in MIC Bias path.
Is MIC Bias 2.1V non
present at R330 or at
the MIC?
Change UEM
Are the audio signals to
UEM OK?
Check audio path through
C330, C331 and associated
passive components. Check
for shorts / low impedance to
GND & opens in series
components. Change
passives w here necessary.
Are the audio signals to
UEM OK?
Change UEM
Does the audio w ork in
a call?
Change UPP_
WD2
END
No
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No
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No
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Audio Troubleshooting
Internal MIC
