Nokia 8310 - FOR YOUR SAFETY; General Safety Guidelines

CONFIDENTIAL 10 (18)
Customer Care Europe & Africa NHM-7 Repairhints
SCCE Training Group Version 1.0 Approved
 2002 Nokia Mobile Phones
Date 28.02.2002
© NMP 2002
Checked by:
SCCE Training Group
Approved by:
SCCE
CHAPTER 5 AUDIO-FAULTS
In case of any audiofault in the phone, the best way to define the fault is to make a call with the defect phone to a proper
working one. In case that you can hear the speech of the proper working phone in the defect one but the other way round the
speech of the defect phone is not audible in the proper working phone you know that the internal microphones signalpath is
responsible for the fault.
Of course you can use the same procedure to check the external audiopathes XMIC and XEAR.
I009 bottomconnector
- check mechanical appearance of bottomconnector I009 in case that internal microphone does not work, external audiopath
seems to be interrupted or headset is not recognized. Retest phone with new connector in case of doubt.
Also ensure that contact pads for connector on PCB are clean.
I005 speaker
- check mechanical appearance of speaker. Change part if spring contacts are bent or soiled. Resistance of speaker normally
is 30Ω. Also ensure that contact pads on PCB are clean.
C151/C155
- check resistance of the double capacitors, which normally is > 20MΩ. Both parts have tendencies to leak and often are
responsible for missing uplink audio (C151 in case of internal -, C155 in case of external audio faults).
D200
- due to the missing possibility of rewriting IMEI and Simlock data after changing UEM D200 it is not useful to change
this part at the moment.
check/change R152,
C166/168.
Probably D200 faulty
check MicBias
2.1VDC
at R152 on active
micro
int. micro faulty
internal audio
does not work
int. speaker faulty
ext. micro faulty
ext. speaker faulty
check XEAR-lines for shorts to
GND and interruption.
Probably D200 faulty
check MIC1N/P for shorts to GND
and interruption, especially check
C151! Probably D200 faulty
check speaker lines for shorts
to GND and interruption.
Probably D200 faulty
check XMIC-lines for shorts to
GND and interruption, especially
check C155! Probably D200 faulty
external audio
does not work
Audio-Faults
change microphone,
retest phone
change speaker,
retest phone
change headset/
bottomconnector,
retest phone
change headset/
bottomconnector,
retest phone
check MicBias
2.7VDC
at R166 on active
micro
check/change R166, C165.
Probably D200 faulty
nOK
nOK
OK
nOK
nOK
nOK
nOK
OK