Nokia RM-57, Руководство по обслуживанию

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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 (Page 6–37) .
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.
Table 11 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.
Note: Blinking pixels are not allowed in normal operating temperatures and light conditions.
RM-57/58
BB Troubleshooting and Manual Tuning Guide
Nokia Customer Care
Issue 1 Company Confidential Page 6–35
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