User Guide

CCS Technical Documentation Troubleshooting Instructions
Issue 1 01/03 ãNokia Corporation. Page 41
Keyboard
faults
4
Are keyboard
light (LED)
turned on ?
Try to change
UI -module. Is it
working now ?
Measure
voltage over C304.
Is it typ. 8.6V ?
Measure
voltage between
V313/3. Is it
typ. 7.2V ?
Set phone to LOCAL mode. Set
VBATT to 4.2V. Start Display
test with Phoenix. Set
"Keyboard lights" ON
UI-board pads fault or
faulty UI-board.
Retest
Check lines of
CALLED1 and
KLIGHT. If lines are
OK change UEM
Check
C302,C303,L300,V30
0, R301, R302, R303,
R325, C304.
If OK change N300
Check V313, V314,
R313, R314
Check CALLED1
(N300/8 and KLIGHT
(V314/IN).Are
they HIGH ?
Measure
voltage X301, pin 1.Is it
typ. 7.2V ?
No
Yes
No
No
Check X301, R307
Yes
No
Yes
No
Yes
No
End
Yes