LG KG300, Service Manual

Page: 26 / 85

4. Troubleshooting
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Display/Illumination problems
Make a general visual inspection for corrosion or oxidation from liquid damage.
Turn the phone on. Check the LCD and the illumination. The illumination is lightened when the phone
starts and will continue for approximately 20 sec
Turn the phone on. Go to service test menu; choose “11. LCD” . You should see a pattern check that
no lines or pixels are missing and that there are no discolorations. If necessary replace the LCM.
If all segments are missing check that the LCD connector (Fig.5.1) and LCD FPC is not mechanical
damaged, dirty or oxidized.
Turn the phone on. Go to service test menu; choose “10. LED” . The illumination should start flashing
(Fig 5.2) .
Check that all 12 Keypad LEDs have the same illumination strength. If necessary replace the LED
with the weakest light. Repeat this step until all LEDs light ever over the keypad.
Fig.5.1
Fig.5.2