Nokia NHM–7 Series Troubleshooting Instructions page 23

PAMS Technical Documentation
Keypad
faults 3
Is volume UP key working ?
Yes
Is volume DOWN key
working ?
Yes
END
Issue 1 10/2001
Measure ROW0
No
line from S301.
Is it ~1.8 V ?
Measure COL1
from S301 when
S301 is pressed
Is there
50us pulse ?
Measure ROW0
No
line from S302.
Is it ~1.8 V ?
Yes
Measure COL4
from S302 when
S302 is pressed
Is there
50us pulse ?
Yes
E Nokia Corporation
Troubleshooting Instructions
Check S301,
S302, lines.
No
If OK change
change UPP
Yes
and COL1 line.
No
If OK change
change UPP
Yes
Change UPP
Check S301,
S302, lines.
No
If OK change
Z301.
If still FAIL
change UPP
No
Change UPP
NHM–7
Z301.
If still FAIL
Check S301
Z301.
If still FAIL
Check S302
and COL4 line.
If OK change
Z301.
If still FAIL
change UPP
Page 23