User Guide

Table 7 Display module troubleshooting cases
Display blank There is no image on the display. The display looks
the same when the phone is on as it does when the
phone is off. The backlight can be on in some cases.
Image on the display not correct Image on the display can be corrupted or a part of
the image can be missing. If a part of the image is
missing, change the display module. If the image is
otherwise corrupted, follow the appropriate
troubleshooting diagram.
Backlight dim or not working at all Backlight LED components are inside the display
module. Backlight failure can also be in the
connector or in the backlight power source in the
main engine of the phone. Backlight is also
controlled automatically by the ambient light
sensor.
This means that in case the display is working
(image OK), but the backlight is not, follow the
Display and Keyboard Backlight troubleshooting.
Visual defects (pixel) Pixel defects can be checked by controlling the
display with Phoenix. Use both colours, black and
white, on a full screen.
The display may have some random pixel defects
that are acceptable for this type of display. The
criteria when pixel defects are regarded as a display
failure, resulting in a replacement of the display, are
presented the following table.
Table 8 Pixel defects
Item White dot defect Black dot
defect
Total
1 Defect
counts
R G B White
Dot
Total
1 1
1 1 1 1
2 Combine
d defect
counts
Not allowed.
Two single dot defects that are within 5 mm of each other should
be interpreted as combined dot defect.
Note: Blinking pixels are not allowed in normal operating temperatures and light conditions.
RM-170; RM-171
Nokia Customer Care BB Troubleshooting and Manual Tuning Guide
Page 6 –10 COMPANY CONFIDENTIAL Issue 1
Copyright © 2006 Nokia. All rights reserved.