Nokia NSB-9 Series Troubleshooting Instructions page 68

NSB-9
Troubleshooting Instructions
Audio
faults 4
Is internal
microphone
working ?
Yes
Audio
faults 5
3) If you don't get such a small signal out from signal generator, use resistor network to attenuate
signal
Page 68
No
Check microphone
connector. Is it OK
No
Try to change
microphone. Is it
working now?
No
Set phone in LOCAL mode. Use Phoenix
"Audio Routing and Test Signals" Test. Set
routing HP in Ext out
Yes
Measure MICB1 voltage
from MICP (J107). Is it
~2.1V ?
Yes
Connect external 1kHz (sine 30mVpp)
audio signal in MICP line and ground line
to MICN line
Measure sine signal
from HSEAR and
HSEAR R lines. Is it
~160mVpp with
headset?
Yes
Retest
Nokia Corporation
CCS Technical Documentation
No
Change defect part and
Yes
Check L110, C153,
No
line. If OK -> change
(3
No
Check R154, C150
retest
Retest
R155, C154 and
UEM
and line. If OK ->
change UEM
Issue 1 04/03