Microphone - Nokia RM-11 Series Troubleshooting Manual

RM-11
Troubleshooting - Baseband

Microphone

Audio
faults,
page 2
Is the microphone
working?
YES
Audio
faults,
page 3
©2005 Nokia Corporation
Page 50
Change the
microphone. Is it
NO
working now?
NO
Set mobile terminal in Local Mode. Use
Phoenix Troubleshooting -> Baseband ->
Audio test
Select the following: Ext microphone in; HP
speaker out; Loop on; Input Hpmic; Output
Hpear; Loop analog. Select 21 dB mic gain,
select -10 dB ear gain, and inject a 1 KZ
sine signal at 20 mVpp on XMIC.
Measure MICB1
voltage from MICP
pads on bottom
connector.
Is it ~2.1V?
YES
Is the signal going
to the UEM at MIC1P
and MIC1N at R172?
YES
Is the signal going
out of the UEM at
XEAR, pin 11, 12, 13,
and 14 on the
bottom connector
(X101)?
YES
Retest
CC Technical Documentation
YES
Check connections
at C175 and R170. If
NO
OK, change UEM.
Check connections at
R171, R172, R170, R173,
C173, C174, C175, C170,
NO
C171, C172. If OK,
change microphone.
Check L103, L104, N150,
C160, C161, C169, C166,
C168, C164, C180, C181,
C183, C184, C185, C112,
NO
C113, C114, C115, R163,
R976, R977, R165, R164,
R112, R113. If OK,
Confidential
Retest
change UEM.
Issue 2 09/2005