Wuxga Lcd Backlight

Wuxga Lcd Backlight

The replacement LCD on my laptop is too dim. What is the problem?

My laptop is a Dell Inspiron 9400. I replaced a broken LG LP171WU1 (WUXGA) with a Samsung LTN170WX-L03 (WXGA). However, when I boot my computer, the replacement screen is only at about 50% brightness.

Changing the brightness in Windows XP does nothing.
Reinstalled Windows, updated drivers, no change.
Changing the brightness in BIOS does nothing. I have the latest BIOS.
Changed the inverter board, no change.
IT IS NOT THE BACKLIGHT.
The screen works perfect in a 9200 series laptop computer.

If I reseat the LCD cable from the motherboard to the screen/inverter during operation, the screen will go to 90-100% brightness, but I still cannot change the brightness through any method.

How can I fix this?
Once I restart the computer, the problem comes back. If I re-seat the connection, it will return to 90-100% brightness, but only until the screen goes to sleep or the computer is shut down.

If you have already tried the inverter there is only two possible reasons that I know of that it could be.

First one which is that the inverter is not grounded correctly (sometimes they are connrected to the LCD screen)

But more commonly it is down to the LCD being a different model which I think is the problem in your case.

Sometimes even just getting the numbers in the brackets different can cause a LCD screen to act up.

I would try matching the exact model number from the original LCD with the replacement and see if you get the same issue.

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