Nokia RM-164, Руководство по обслуживанию

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User interface troubleshooting
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
Phoenix
.
Table 11 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.
This means that in case the display is working
(image OK), the backlight is faulty.
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 12 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 Combined
defect counts
Not allowed.
Two single dot defects that are within 5 mm of each other should be
interpreted as combined dot defect.
RM-164
BB Troubleshooting and Manual Tuning Guide
Issue 1 COMPANY CONFIDENTIAL Page 3 –21
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