Nokia 8310 Repair Hints page 12

Customer Care Europe & Africa
SCCE Training Group
© 2002 Nokia Mobile Phones
CHAPTER 7 USER INTERFACE FAULTS
Display faulty
change displaymodule I004 to check if it is responsible for the fault
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check mechanical appearance of displayconnector X300, change part if necessary
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- if fault persists check VIO 1.8VDC and VFLASH1 2.8VDC, both measurable at double capacitor C303
also check VOUT 8.1VDC at C301/302 which is generated by the displaymodule.
- If DC-voltages are ok but display does not work, probably UPP D400 faulty.
Note that you have to make SW-update after changing UPP, otherwise the phone will not switch on!
Display- and keyboardillumination faulty
- check VBAT 4VDC at R304 and R307
check that voltage at V300/301 pin 5/6 decreases from 3.5VDC to 3VDC if illumination gets active, check R305 (470Ω) or
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change V300/301 if necessary.
It also is possible that UEM D200 faulty, but do not change this part since there is no possibility to rewrite phonedata.
in case of faulty keyboardillumination also check mechanical appearance and solderings of board to board connector
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X303
Buzzer faulty
ensure that fault is no result of too old phonesoftware. SW-version should be 4.04 or newer.
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if SW-update does not solve the problem, activate buzzer with Phoenix in menu "Maintenance/Testing/Audio Test".
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Check VBAT 4VDC and PWM-signal coming from UEM at buzzer, change buzzer if necessary
it also is possible that UEM D200 is defect, but since there is no possibility to rewrite phonedata after reworking UEM
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you should not change this part.
Vibramotor faulty
as in case of faulty buzzer ensure that fault is not the result of too old phonesoftware, make SW-update if necessary
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- check spring contacts of vibramotor if bent or soiled, change vibramotor if necessary
if fault persists probably UEM D200 faulty. Do not change this part since there is no possibility to rewrite phonedata
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after changing UEM
Keyboard faulty
if only a single key does not work displaymodule I004 is faulty in all probability. Exchange displaymodule and retest the
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phone
- in case that a whole row or column of keys (e.g. 2-5-8-0) does not work this also may be caused by a defect displaymodule,
but it is more likely that EMI-filter Z301 interrupts the keyboardlines or UPP D400 is faulty. Also check solderings and
mechanical appearance of board to board connector X303, change part if necessary.
Note that you have to flash the phone after changing UPP, otherwise the phone will not switch on!
© NMP 2002
CONFIDENTIAL
NHM-7
Date 28.02.2002
GND
VBAT
Checked by:
SCCE Training Group
12 (18)
Repairhints
Version 1.0 Approved
GND
PWM
Approved by:
SCCE