User Guide

6255/6255i6256/6256i (RM-19)
Baseband Description and Troubleshooting Nokia Customer Care
Page 64 ©2005 Nokia Corporation Company Confidential Issue 2 05/2005
UI Modules
Keypad
faults,
page 2
Are UI modules
keys working?
Change keypads
module. Is it
working?
NO YES
Make sure there
are no shorts on
Z2400. Is it OK?
Change Z2400
Retest
NO
NO
NO
YES
END
YES
Measure ROW0-4
Keyb(5) and
Keyb(9) signals
between UPP and
Z2400. Are they
~1.8V?
Retest
Change the UPP.
YES