Keyboard Faults 3 - Nokia NPL-4 Series Troubleshooting Instructions

Nokia Customer Care

Keyboard faults 3

Keyboard
faults
3
Is volume up key
working ?
Yes
Is volume down key
working ?
Yes
Keyboard
faults
4
Copyright © 2005 Nokia Corporation. All rights reserved.
Issue 2 05/05
Company confidential
Measure ROW0
line from S300.
Is it ~1.8v ?
No
Measure COL0 from
S300 when key is pressed.
Is there 50us pulse ?
Measure ROW1
No line from S301.
Is it ~1.8v ?
Measure COL0 from
S301 when key is pressed.
Is there 50us pulse ?
Troubleshooting Instructions
Yes
No
No
Yes
Yes
No
No
Yes
NPL-4/5/
Check S300, S301,
S303 and lines. If OK
change Z300.
If still fail change UPP
Check S300 and COL0
lines. If OK change
Z300.
If still fail change UPP
Change UPP
Check S300, S301,
S303 and lines. If OK
change Z300.
If still fail change UPP
Check S301 and COL4
lines. If OK change
Z300.
If still fail change UPP
Change UPP
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