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 35
IHF
Figure 28: IHF troubleshooting
IHF
troubleshooting
Set phone audio routing from a
known working MIC input to
PAOUTP & PAOUTN. Ensure
that correct MIC bias is on.
Check IHF speaker
contacts and PWB pads. Check that
speaker impedance is 8 ohm.
Is it ok?
Clean contacts /
replace IHF speaker /
IHF connector
Is VBAT provided to N607?
(check at C616)
Change N607
Change UPP_WD2
Replace defect
components
Change UEME
Check passives
around N607, change
parts if necessary
End
Check audio path from N607 to
IHF pads. Check passives around
N607. Check for shorts to GND
or between the lines. Change
passives where necessary
Check voltage at J380.
Is it 1.8V ?
Is the
DC bias (1/2 VBAT)
measurable on the input path
of N607? (check at R611
& R612)
Is the DC bias voltage
(1/2 VBAT) measurable at
the IHF speaker pads?
Are C611, C612, R611 and
R612 ok?
Change UPP_WD2
no
no
yes
yes
VBAT line failed
around N607. Swap
engine board.
yes
no
no
yes
no no
yes
Change N607
Is the
DC bias (1/2 VBAT)
measurable on the IHF
speaker pads?
Connect
headset HDB-4 to X132,
activate audio routing from
ext. MIC to IHF. Check audio
signal at IHF pads with
oscilloscope.
Is it ok?
Check
audio signal at IHF pads with
oscilloscope. Is it ok?
Does audio work in a call?
no
yes
no
yes
yes
no
yes
yes
yes
no