Liquid-crystal display (LCD) has surpassed cathode-ray tube (CRT) and plasma to become the world’s most popular display technology. More display devices use LCD technology than all other display technologies. While popular, though, some LCDs may suffer from screen flickering.

Screen flickering is a phenomenon in which the image produced by a display device flashes or flickers. It’s not exclusive to LCDs; other types of display devices can suffer from screen flickering as well. Nonetheless, screen flickering in LCDs is often caused by the following.

Edge-Lit Backlighting

LCDs with edge-lit backlighting are more likely to suffer from screen flickering than those with full-array backlighting. All LCDs require backlighting. Unlike organic light-emitting diode (OLED) displays, LCDs don’t have self-illuminating pixels, so they require backlighting.

Some LCDs feature edge-lit backlighting consisting of bulbs around the perimeter of the display. Others feature full-array backlighting consisting of a grid of bulbs. Those with edge-lit backlighting are more likely to suffer from screen flickering.

Loose Cable Connection

Sometimes all it takes to cause screen flickering is a loose cable connection. Depending on the specific type of LCD, it may require a cable connection. Computer monitors, for instance, must be connected to a computer with a cable. If the cable is loose, the LCD may turn it, but it could experience screen flickering. If you notice screen flickering when using an LCD monitor, check the cable to ensure that it’s properly seated in the port.

Low Refresh Rate

Perhaps the most common cause of screen flickering in LCDs is a low refresh rate. All display devices have a refresh rate. It’s the speed at which a display device is able to change or update its image. Refresh rate is measured in Hertz (Hz), which is the equivalent of frames per second.

An LCD with a 100 Hz refresh rate will be able to change its image 100 times per second. An LCD with a 50 Hz refresh rate, on the other hand, will only be able to change its image 50 times per second.

Malfunctioning Video Card

A malfunctioning video card can cause screen flickering as well. Computers have a video card. The video card processes data so that it can be displayed by the monitor. If the video card fails, the monitor may experience screen flickering.

Video cards can also suffer from a loose connection. If the video card is loose, it may cause screen flickering. You should double-check the video card if you experience this phenomenon with an LCD monitor.