Nokia 500, Руководство по обслуживанию

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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.
Note: Always use the display with the phone's window while checking the display's visual
functionality.
The second step is to check that the 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 the 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.
Pixel defects
Table 5 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.
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.
Visual defects (pixel) Pixel defects can be checked by controlling the
display with Phoenix. Use both colors, black and
white, on a full screen. R, G, B are also helpful.
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 in the following table.
Table 6 Pixel defects
Bright sub-pixels (sometimes called on-pixels or stuck-on) are
characterized by the appearance of bright/colored
pixels in, for example, black full screen picture.
Dark sub-pixels (sometimes called off-pixels, stuck-off, or black
pixels) are characterized by the appearance of dark
pixels in white, red, green, or blue full-screen
picture.
Combined sub-pixel defects are characterized by at least two sub-pixels
defects (bright or dim) being closer than 5 mm to
each other.
RM-750
BB Troubleshooting and Manual Tuning Guide
Issue 1 COMPANY CONFIDENTIAL Page 3 – 17
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