Display Module Troubleshooting; General Instructions For Display Troubleshooting - Nokia 3555 Service Manual

Display module troubleshooting

General instructions for display troubleshooting

Context
• The 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.
• The operating modes of the display can be controlled with the help of
Display blank
Image on the display not correct
Backlight dim or not working at all
Visual defects (pixel)
Steps
1. Verify with a working display that the fault is not on the display module itself.
The display module cannot be repaired.
2. Check that the cellular engine is working normally.
i To check the functionality, connect the phone to a docking station.
Phoenix service software.
ii Start
3. Proceed to the display troubleshooting flowcharts.
Use the Display Test tool in
Display troubleshooting
Context
There are three different display fault cases;
Page 3 –28
Table 7 Display module troubleshooting cases
Phoenix to find the detailed fault mode.
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BB Troubleshooting and Manual Tuning Guide
Phoenix .
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 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 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.
This means that in case the display is working
(image OK), the backlight is faulty.
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.
RM-257; RM-270; RM-277
Issue 1