How To Do A Backlight Bleed Test

Backlight bleeding, also known as lightbleed, is a defect that can affect LCD TVs or computer screens. This issue causes excessive white light to bleed around the edges of the screen, which can distort images. You will learn about the technical aspects of blacklight bleed, how to identify it and what you can do if the problem is affecting your screen.

Backlight Bleed Definition

All modern LCD screens use a light source to project images onto the display. This is typically accomplished by an LED light source projecting light onto an LCD filter. The LCD reacts by displaying the proper colors and images. The bevel of your screen is made to block the light so that none of it escapes and goes beyond the LCD layer.

Problems start when this bevel doesn’t properly block light. Instead of blocking the light and keeping the colors consistent on the screen, some of the light bleeds out from the side and distorts colors in that sector. This usually affects the corners and sides of the screen.

Identifying Backlight Bleed

Testing for backlight bleed is easy. Find either an image or video that is completely black. You can find plenty of these online with a brief search. You can technically do this with any type of video or image, but black is the best because it requires light from the LED but contrasts the white color of the light so that you can easily see anything bleeding through.

Turn down the lights in your room and look around the computer or TV monitor. You can typically see blacklight bleed from any angle, but sometimes it only appears from the side. If the screen is good, then you shouldn’t see anything aside from the black color. If there is bleeding, then you will see that the corners or sides are noticeably brighter than the rest of the screen.

Sometimes you might misidentify a screen as having backlight bleed if it uses an IPS light source. Usually you can correct this by just turning down the brightness a little until the glow goes away.

Correcting the Issue

There are a few methods that may be able to fix the issue, but usually it’s best to return the monitor if possible for a new one. The easiest method is turning the brightness down until the bleeding isn’t as noticeable. This can work with minor bleeding issues, but severe issue might require the brightness to go down to its lowest setting.

Another easy method is rubbing a microfiber cloth near where the bleeding is occurring. This can help tighten the area and block the light.

The other two methods require working on the monitor itself. This may void your warranty, so returning is usually the preferred option. The first method is to slightly loosen the screws at the back of the monitor. This might cause the light to bleed out the sides of the monitor rather than the display itself.

The last method requires dismantling the monitor until the LCD is exposed. Adhere dark electrical tape around the edges of the LCD. Be careful to only tape the edges as going in too far may darken images on the computer or TV. This will provide an extra barrier against the light bleeding through.

 

Steps to Prevent Backlight Bleed

There are a few things that you can do to decrease the chances of backlight bleeding, but sometimes you can do all the right things and it will occur anyway. Some monitors are just defective and bleeding will occur no matter what.

Regardless of this, these steps will help maintain your monitor in general so that it operates at peak proficiency. Don’t keep the brightness too high as this can tax the equipment and make it degrade faster than expected. It’s also a good idea to turn the monitor off when possible. Some people keep their computers running all the time and this can be problematic. Try reducing any physical damage to the monitor by limiting activity around the immediate vicinity. You don’t want someone to accidentally bump into the monitor and damage it.

 

Monitor Arrives with Backlight Bleed

You should immediately return a new monitor if it has backlight bleed. While this is a rare occurrence, it can happen. Unless there is something preventing you, such as the store not accepting returns because the monitor was on clearance, you should get a new one that isn’t defective.

While you can try to fix the monitor, it’s easier and recommended to just return it. As stated above, the methods for fixing backlight bleed aren’t always effective and they may void the warranty.

 

Conclusion

Backlight bleeding isn’t the worst issue that can affect your TV or computer monitor, but it certainly is annoying. You’ll notice that colors are incorrect near the corners or sides because of light escaping through the barrier around the edges of the monitor. While there are steps you can take to fix the issue, they don’t always work and it’s often best to return the monitor if possible. If not, then try to methods mentioned above and you may be able to correct the problem.