22 Jun, 2009
Troubleshooting on laptop screen backlight issues
Posted by: Ecomer In: LCD Screen Repair ()
The laptop repair often comes with the screen issues. The laptop LCD screen is black, but an external monitor works fine on laptop.
To identify what the problem of the LCD screen is, we often make a test first. Connecting the laptop to an external monitor, if it works fine, then we know the video card is in good condition. It means that the screen still gets data signal from the video card, but for some reason the backlight lamp doesn’t work.
About the backlight issue, we need to know what cause the problem. At first, let’s check the lid close switch. The lid switch is a small button close to the LCD screen. If the lid swith cannot move freely or be dirty, it may get stuck inside the laptop and cut off the power from the inverter board. We know that the inverter board supply power to light up the backlight lamp. If it cannot work, so does the backlight.
Except the case, let’s check the inverter board. The screen is black, but there’s still an image on it. The problem is most likely on it. If not like this, please connect another inverter board. Replacing a new inverter board, but the screen is still dark. Then the problem is not related to the inverter board.
Now let’s make the last test, disconnecting the old backlight and replacing another backlight to the inverter board. If the new one works well, then there must be some problems with the backlight lamp.Please make sure the connector on the backlight lamp is similar to the connector on your LCD screen.
As we find out the problem, we just need to replace the backlight.

