Nokia NHM-7 series Service Manual page 135

NHM–7
PAMS Technical Documentation
Troubleshooting Instructions
Earpiece
2
Connect EXT audio signal 1kHz
(sine) (¨200mVp–p) in XMICP pads
and Ground in XMICN
Measure sine signal
Measure sine signal
No
Yes
from UEM (R156) Change UEM.
from earpiece pads.
Is it ~130mVp–p ?
Is it ~880mVp–p ?
No
Yes
Check R156, C153,
C155, R166, R167,
Retest
C163, R161 and
line.
E Nokia Corporation
Page 15
Issue 1 10/2001