User Guide

Nokia Customer Care 6(a) - Baseband Troubleshooting
Company Confidential RH-51/52, RH-67/68
Issue 3 09/2004 © 2004 Nokia Corporation. Page 31
Audio troubleshooting
Internal microphone
Figure 24: Internal microphone troubleshooting
Internal
microphone
faulty
Set phone audio routing from
MIC1 (hand portable) to known
working audio output (i.e. EAR
(HP) or HF/HFCM (Ext)).
Ensure mic bias (MICB1) is on.
Is MIC bias
2.1V present at the
microphone?
Check mic
module and PWB contacts.
Are they ok?
Clean contacts /
replace mic module
no
Check R604, R607,
C605 and other
passive components in
MIC bias path
Passive
components ok? (correct
value/ no short circuit to
GND)
Change UEME
Change
defect parts
Are the
audio signals to
UEME ok?
Check audio path
through C606, C607
and associated
components
Passive
components ok?
(correct value/ no short
circuit to GND)
Change UEME
Change
defect parts
Does
audio work in
a call?
Change
UPP_WD2
End
yes
yes
yes
no
no
no
yes
no
no
yes
yes