Baseband Troubleshooting Instructions
CCS Technical Documentation
Page 56
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Nokia Corporation
Issue 1 10/02
Is volume DOWN key
working?
Measure ROW0
line from S302.
Is it ~ 1.8 V?
No
Check S301,
S302, and lines.
If OK ->
change Z301.
If still fail ->
change UPP.
No
Yes
Change UPP
No
Yes
END
Keypad
faults 3
Yes
Is volume UP key
working?
Measure ROW0
line from S301.
Is it ~ 1.8 V?
Check S301,
S302, and lines.
If OK ->
change Z301.
If still fail ->
change UPP.
No
No
Measure
COL1 from S301
when S301 is pressed.
Is there a 50 us
pulse?
Yes
Check S301
and COL1 line.
If OK ->
change Z301.
If still fail ->
change UPP.
No
Change UPP
Yes
Yes
Check S302
and COL4 line.
If OK ->
change Z301.
If still fail ->
change UPP.
Measure
COL4 from S302
when S302 is pressed.
Is there a 50 us
pulse?