Display module troubleshooting
General instructions for display troubleshooting
The first step is to verify with a working display that the fault is not on the display module itself. The display
module cannot be repaired.
The second step is to check that the cellular engine is working normally. This can be done by connecting the
phone to a docking station and starting Phoenix service software. With the help of Phoenix read the phone
information to check that also application engine is functioning normally (you should be able to read the
APE ID).
After these checks proceed to the display troubleshooting flowcharts. Use the Display Test tool in Phoenix to
find the detailed fault mode.
Operating modes of the display
Display is in a normal mode when the phone is in active use.
Display is in a partial idle mode when the phone is in the screen saver mode.
Display is in OFF mode when the phone is in the full idle mode (idle LED is flashing).
The operating modes of the display can be controlled with the help of Phoenix.
Table 13 Display module troubleshooting cases
Display blank
There is no image on the display and Idle LED does
not flash. 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 part of the
image can be missing. If part of 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 table below.
RM-132; RM-133
BB Troubleshooting and Manual Tuning Guide
Nokia Customer Care
Issue 1
COMPANY CONFIDENTIAL
Page 6 –41
Copyright © 2006 Nokia. All rights reserved.
