Backlight screen not working

i have my dell 7586 which is working it has image but no lights on its screen. i know its been from spill of water or something i already check the board i dont see anythong burn out on parts. i there will be some sort of diagram were the light ways is i may solve my problem some says there is fuse for lights. hope this image can help thanks and more power..

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She Daras post some really good pictures of both sides of your mother board with your question. That way we can at least try to help you. A schematic is not going to work unless your have the boardview for this board as well. Adicionar imagens a uma pergunta já existente


What is the board number of the motherboard?

Knowing this will help to find the schematics, if there are any available online that is.


this is my board id 8706-1 BIOS RO 17.17 WHL 2G H3KD8 hope it helps a lot.


@She Daras

Unfortunately I cannot find a schematic for the motherboard.

I think that your model has a 30 pin video cable from the motherboard to the LCD screen.

If this is correct then on a lot of 30 pin video cables the power for the backlights are on pins 26, 27, 28 & 29.

Use a Voltmeter to check if there is voltage on all these pins. BE VERY CAREFUL that you do not short out the pins when testing for the voltage. Test between the pins (one at a time) and an earth point on the motherboard.

IF the voltage is present then the problem may be with the BL-EN lead. This is the backlight enable lead.

Power is always available to the LCD screen and a voltage is applied to the BL-EN lead (usually about +3.3V DC) to signal the LCD screen to turn on the backlights. The voltage is removed if the backlights are to be turned off e.g. sleep mode. With a lot of 30 pin connectors the BL-EN lead is on pin 22.

Again this pin numbering may NOT be the case for your screen backlight circuit then maybe if you can't find the schematics another option is to find out the make and model number of the LCD panel (look on back of panel itself) and then search online for "(insert make and model number of LCD panel) pinout" or datasheet". This will give the numbering of the pins and what they do and it will correspond to what is on the motherboard.

At least this way you will know if it is a power supply problem or a power on/off problem


thank you so much for a little guide instructions for troubleshooting ill try this hope it works.


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