Audio Problem - Nokia NHM-1 Series Troubleshooting Instructions

CCS Technical Documentation

Audio problem

Start
No
Is earpiece working?
Yes
Set phone in LOCAL mode. Use Phoenix audio test.
Measure DC voltage between earpiece
pad and GND. Is it ~1.38V ?
Continue
Issue 1 11/03
Try to change earpiece.
Is it working now?
No
Set EXT IN, HP OUT, LOOP ON
Yes
Measure MICB2 voltage
from MIC2P (L102).
Is it ~2.1V?
Yes
Connect EXT audio signal (1kHz sine,
200mVpp) in XMICP and GND in XMICN.
Measure sine signal from
earpiece pads.
Is it ~170mVp-p?
Yes
retest
Nokia Corporation.
Troubleshooting instructions
Yes Retest earpiece
Check L102, R116, R117, C110,
No
C111, X100, X166 and lines,.
If OK change UEM
Check X102, L102, C105, C107, C114,
No
C117, R108, R110 and line.
.
If OK change UEM
Check X102 , C105 , C106,
C112 , C113 , C114 , C115,
No
C116 , C117 ,R102 , R104
R109 , R111 , L102. If OK
check UEM.
NHM-1
Page 45