User Guide

Display troubleshooting

Context

• The display is in a normal mode when the phone is in active use.

• The operating modes of the display can be controlled with the help of Phoenix.

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.

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 in the following tables.

Table 8 Minimum distance between dot defects

Internal defect Bright dot 0

Dim dot 2

(Total 2)

Table 9 Visual defects

Visual defects Allowable (mm)

Bright dots None

Dim dots S < = 5

Any allowable defects S < = 5

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.

RM-348; RM-349; RM-350

Baseband Troubleshooting

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