LCD screens are a user friendly piece of technology because they don't take up any room when compared to old rear-projection screens and the picture quality and lack of glare is easy on the eyes. All the magic in a LCD screen happens because of a long light bulb that lights up the entire screen. When this bulb burns out, you'll have to replace it in order to get your screen back in working order. Luckily, the symptoms leading up to a burnt LCD bulb and the tell-tale signs of a dead bulb are easy to recognize.
Watch for a red or pinkish hue at the bottom of your LCD screen. This is a classic sign that your LCD bulb is burning out and does not have much time left. The hue will eventually go away if the screen is left on long enough, but don't let the fact that the symptom went away fool you. If you see the red/pinkish hue, it's time to replace the bulb.
Look at how bright the image is on the screen. The bulb is dying if it is not nearly as bright as it used to be. You can make sure it isn't a problem with your screen's settings by changing the brightness and contrast on the screen. More than likely though, a dim screen means it's time to replace the bulb.
Watch for flickering on your screen. This is a sign that your LCD bulb is struggling to stay on. This is usually one of the last signs you'll see before the bulb burns completely out.
Replace the LCD bulb immediately if the LCD screen is completely black but the device, whether a laptop or television, is on. This means the bulb has completely burnt out. At this point, you can't hope to squeeze a little more life out of the bulb by trying to turn your device on and off. Replacing the bulb is your only option.