CCS Technical Documentation
Troubleshooting - Baseband
RH-34
Issue 1 11/2003 Confidential
©
2003
Nokia Corporation
Page 43
Microphone
Audio
faults,
page 2
Audio
faults,
page 3
Is the microphone
working?
Change the
microphone. Is it
working now?
Retest
Set phone in Local Mode. Use
Phoenix "Baseband Audio
Control" and set the following:
Enable Tx, Enable Rx, Select
MIC1, Enable HF only
(differential). Talk through the
microphone.
Measure MICB1
voltage from MICP
pads on bottom
connector.
Is it ~2.1V?
Is the signal going to
the UEM at MIC1P
and MIC1N at R172?
Is the signal going
out of the UEM at
XEAR, pin 11, 12, 13,
and 14 on the
bottom connector
(X101)?
Check connections
at C175 and R170. If
OK, change UEM.
Check connections
at R171, R172, R170,
R173, C173, C174,
C175, C170, C171,
C172. If OK, change
microphone.
Check L103, L104,
N150, C160, C161,
C169, C166, C168,
C164, C180, C181,
C183, C184, C185,
C112, C113, C114,
C115, R163, R976,
R977, R165, R164,
R112, R113. If OK,
change UEM.
Retest
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES