Microphone - Nokia RH-44 Series Troubleshooting - Bb

CCS Technical Documentation

Microphone

Audio faults 2
Is microphone
working?
Yes
Audio faults 3
Issue 1 04/2003
Change microphone.
No
Is it working now?
No
Set phone in LOCAL mode.
Use Phoenix "Baseband
Audio Control" and set the
following: Enable Tx, Enable
Rx, Select MIC1, Enable HF
only (differential ended). Talk
through microphone.
Measure MICB1
voltage from MICP
pads on bottom
connector. Is it -2.1V?
Yes
Is signal going to UEM
at MICP and MICN at
L122 and C174?
Yes
Is signal going out of
UEM at XEAR, pin 10
on bottom connector?
Nokia Corporation
Troubleshooting — BB
Re-test
Yes
Check C195, R176,
R178. If okay, change
No
If connection is OK at
C174 and L122, then
No
change microphone.
Check signal at R160.
No
If OK, change UEM.
Yes
Confidential
RH-44
UEM.
Re-test
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