Nokia NSB-9 Service Manual page 249

CCS Technical Documentation
Keypad
faults 4
No
Are engine
QWERTY
keys
working?
Yes
Keypad
faults 5
Issue 1 04/03
Is it a S306 that is
not working (SHIFT
key)
No
Measure voltage of
keypad ROW
where faulty key is
located. Is it ~1.8V
Yes
Check keypad
COLUMN where faulty
key is located. Is there
a pulse sequency
every 50ms when
faulty key is pressed
down
Yes
Check switch and lines of
faulty key. In case of column
4 or 5 check also R330,
Change
R331, R315. If OK change
UPP Z301. If still not OK change
Nokia Corporation
Troubleshooting Instructions
Check switch S306,
Yes
R316, Genio 19 line
and VIO voltage at
R316 ~1.8V. OK?
Yes
Change
UPP
Check keypad
No
switch and lines,
R330, R331, R315.
Are they OK?
Yes
Check switch and lines of
faulty key. If OK change
Z301. If still not OK
change UPP.
No
UPP.
NSB-9
No
Change
defect part
No
Change
defect part
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