Advertisement
Customer Care Europe, Middle East & Africa
SCCE Training Group
CHAPTER 10: INTERNAL AUDIO FAULTS
In case of any internal audio-fault in your phone, the easiest way to define the fault is to establish a call to the defect
phone with another proper working one. In case that you can hear the speech of your colleague in the defect phone but
your colleague cannot hear your speech, you know that you have to search in the microphones signal path for the fault.
The other way around, if your colleague can hear you but you cannot hear your colleague you know that you have to
search in the speakers signal path for the fault, assumed that you are holding the defect phone.
No audio from
microphone
Change microphone,
check function
nOK
Check MicBias at
V413 pin 5: 2.4 V on
active mic
O K
Check connection
between C120 and
Mic-pads on PCB
O K
C h a n g e C O B B A N 1 0 0
Speaker faulty
Check if resistance of speaker is 30 ? .
-
Check mechanical appearance of speaker if audio signal is too low or distorted.
-
Check solderings and resistance of R119/120 (22 ? ), change parts if necessary.
-
Check resistance of speaker lines to ground, should be > 0.5 M? . If resistance is not ok especially check capacitors
-
C104 and C124-126 for shorts to ground.
If all above mentioned is ok but speaker does not work, it is necessary to change the COBBA N100.
-
Note that you have to rewrite SIMlock-data, make SW-update and retune RX/TX-values after changing this part!
Microphone does not work
Check/change microphone.
-
Ensure that pads for microphone on PCB are clean.
-
Check bias voltage for microphone at V413 pin 5, 2.4 V on active micro.
-
If voltage is not measurable check V101 and R107/115, change COBBA N100 if necessary.
-
If bias voltage for microphone is ok, check audio lines for disconnection and shorts to ground.
-
Resistance of MICN-line to ground normally is 1 k? while resistance of MICP-line to ground is >30 M? .
-
Especially check C403 and V413 if values are uncorrect. To ensure function also check C120 and L402.
If fault persists change COBBA N100 with µBGA rework station.
-
Note that you have to rewrite SIMlock-data, make SW-update and retune RX/TX-values after changing this part!
© NMP 2002
Flowchart 10-1
Check parts around V101,
check MIC-lines for shorts to
nOK
ground, change N100
Check solderings and
nOK
resistance of L402, also
check C120.
CONFIDENTIAL
NHM—2/5/6
3410
Date 20.11.2002
No audio from
speaker
Check resistance of
speaker (30 Ohm),
change if bent or
soiled
OK
Check connection between
speakerpads on PCB and
C124. Not OK-check
R119/120
OK
Check resistance of
speakerlines to GND,
b o t h > 0 . 5 M O h m
OK
Change COBBA
N 1 0 0
Checked by:
Customer Care E&A
30 (44)
Repairhints
Version 4.0 Approved
Approved by:
SCCE Training Group
Advertisement
