User Guide

NPM-6/6X Company confidential
Troubleshooting Instructions CCS Technical Documentation
Page 42 Copyright Nokia. All rights reserved. Issue 2 06/03
Keyboard
faults
3
Is volume up key
working ?
Measure ROW0
line from S300.
Is it ~1.8v ?
Check S300, S301
and lines. If OK
change Z300.
If still fail change UPP
Check S300 and COL1
lines. If OK change
Z300.
If still fail change UPP
Measure COL1 from
S300 when key is pressed.
Is there 50us pulse ?
No
Yes
No
No
Change UPP
Yes
Measure ROW0
line from S301.
Is it ~1.8v ?
Check S300, S301 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
Measure COL4 from
S301 when key is pressed.
Is there 50us pulse ?
Yes
No
No
Change UPP
Yes
Is volume down key
working ?
Keyboard
faults
4
Yes
No
Yes