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398LM panel backlight out

Display contrast adjustment instructions did not work. How to fix backlight?

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Best quality picture

This is likely a simple settings issue.

A lot of people don't realize that backlight settings can affect the picture.

Go to the menu (press menu on your remote)

The menu will show picture options. Just toy with different settings until you find what you want. It may be on a preset setting that doesn't work. If you are in a bright room, you will need to increase brightness and contrast and perhaps backlight.

Usually an unclear picture is due to the contrast, backlight, and brightness settings being too low. You can also increase sharpness.

I suggest a contrast setting of 70, a brightness setting of 60-80, and a backlight setting of above 80.

Good luck.,

Mar 08, 2014 | Hisense 50 Class LED HDTV - 1080p, 1920x...

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Liftmaster Smart Control Panel (398LM) does not work

Hi ,
i think internal power supply unit problem.


Jan 20, 2014 | liftmaster 398LM Smart Control Panel

1 Answer

Sharp lg-32bx6m, contrast light is not enough, how can i fix this problem

Select menu, display settings, select brightness/contrast/sharpness etc. and adjust these to your likings.

Jul 27, 2012 | Sharp LC32BX6M TV

1 Answer


Brightness can be adjusted by the hotkeys or within windows (system settings - backlight).
contrast can be adjusted with a potentiometer at the mainboard.
normally contrast does not change over the lifetime (my oldest 3090 is used 8h/day for 7 years)

some of the old 3090 have a CCFL backlight which dramatically losing brightness when getting old. you have to replace the tube or display unit.

Jul 09, 2012 | Symbol Motorola MC3090 Handheld Computer

1 Answer

Lost its brightness and clarity

Check whether the backlights get full brightness as you increase the bright ness level. Set the set to least contrast level, and check whether the backlight is sorking well. If it is OK, then try to increase the contrast level [to at least 70% of the total]. If backlight level cannot be adjusted according to the contrast level the backlight inverter baord and backlight CCFL lamps need to be checked.
images of the backlight inverter board and CCFL lamps are attached here.

Feb 21, 2012 | Toshiba 42HP66 42 in. LCD Television

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Psr-s500; no display at all but everything else is working properly.

Read your manual about a contrast control for the display. At one end of the range of control the display is almost invisible. Sometimes there is a little shaft/knob on the back, other times it is a menu item and yes, it is hard to see the display to adjust the display... just go through the procedure blindly to see if it comes back. Also illuminate the display if dark with a flashlight and see if there are display characters there but just lacking a backlight. A backlight failure could be the problem.

Aug 27, 2011 | Yamaha PSR-S500 Digital Keyboard

1 Answer

When i turn on my tv the picture is fine then it goes darker and it stays darker

First things is check the picture adjustment.Try to adjust the brightness and contrast.If did not work the problem is the backlights of the LCD. Usually in that case the problem is loose connection in the backlights connector. The backlights have high voltage so it may cause of overheat at the connector.So try to check the connection of the backlights at the board of your television.Remove the back cover of the TV and look the conector of the backlights and try to resolder and fix it. Thanks!!!!

Aug 21, 2011 | LG Televison & Video

1 Answer

My lcd backlight is very pale, how can I encence the brightness??

Reading your user manual on page 12, bullet 9 you will find the method of changing the contrast of the display. There is no brightness adjustment possible, however the contrast DRASTICALLY affects the readability of the display.

Jul 23, 2011 | Korg PA500 61KEy PROFESSIONAL ARRANGER...

2 Answers

White screen on the dbx driverack pa? how to fix?

You can adjust the LCD contrast by pressing the Utility button and turning the dial one way or the other. Pressing the Utility button toggles back and forth between LCD contrast and Compressor/Limiter Threshold Meters, so since you can't see anything in the window you may have to press Utility twice, though I think LCD contrast is the first option.

Jan 17, 2010 | DBX Driverack-Pa Eq/Speaker Control System...

1 Answer

Dark screen

if the picture is REALLY dark, like you can just barely see it in a lit room, then the backlight might not be lit. LCD TVshave backlight that shines through the LCD screen which allows you to see the picture.

If it's not the backlight then it would be the brightness/contrast settings that need to be adjusted. If the picture used to be normal and all of a sudden went dark, verify the backlight. Normally you can look through the slots on the top of the set and determine if the backlight is on. If you can see a bright light through any of the slots, the backlight is probably OK... go after the brightness/contrast settings.

Mar 25, 2008 | Vizio L37 Television

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