User Guide

NPL-4/5 Company confidential
Troubleshooting Instructions Nokia Customer Care
Page 76 Copyright © 2004 Nokia Corporation. All rights reserved. Issue 1 05/04
Keyboard faults 2
Keyboard
faults
2
Is UI-module
keymatrix working ?
Try to change
UI -module. Is it
working now ?
Measure SLEEPX signal
from J403 when key
pressed.
Is it ~1.8V ?
When keypad is
pressed, the LED's are
turned on ?
Faulty UI-module.
Retest
Check ROW0-4 lines,
X301. If OK change
Z300. If still fails change
UPP.
Check ROW0-4 lines,
X301. If OK change
Z300. If still fails change
UPP.
Check ROW0-4 lines,
X301. If OK change
Z300. If still fails change
UPP.
Measure ROW0-4
lines from X301.Are
they HIGH ?
No
Yes
No
No
Yes
No
Yes
No
Keyboard
faults
3
Yes
Display
faults
Yes