NHL-10
Baseband Troubleshooting
CCS Technical Documentation
ISSUE 2 01/2004
COMPANY CONFIDENTIAL
31
Copyright © 2003 Nokia. All Rights Reserved.
IHF
Figure 24: IHF troubleshooting
See the following flow chart
I
s
di
I
START
Check IHF speaker contacts and
PWB pads. Are they OK?
Clean contacts / replace
the IHF speaker (B340) &
gasket.
Set Phone Audio Routing from a
know n w orking MIC input, MIC1
[HP, int] or MIC2 [Ext, XMIC] to
HF/HFCM. Ensure the correct
MIC Bias is ON.
No
Yes
Audio Troubleshooting
IHF
s the DC Bias voltage
een on the IHF
fferential paths at the
HF speaker pads?
Is VBATHF present?
Check R362 & R363 for
low impedance.
No
No
Is the Boomer enable
line high (check at
J330)?
Yes
Change UPP_
WD2
No
Is the HF/HFCM DC Bias
seen on the input path
to Boomer at C338 &
C337?
Yes
Follow the trouble-
shooting flow chart for
External earpiece faults.
No
Check audio path from Boomer
(N330) to the IHF pads through
L359 & L360. Check for shorts /
low impedance to GND or
betw een the lines. Also check
passives around Boomer,
especially R336 to R338. Change
passives w here necessary.
Is the DC Bias voltage
seen on the IHF
differential paths at the
IHF speaker pads?
Yes
Change Boomer
(N330)
No
Yes
Yes
