Does your liquid-crystal display (LCD) show permanent lines that aren’t supposed to be there? In some cases, turning the LCD off and back on may solve the problem. Unfortunately, though, this doesn’t always work. There are instances in which an LCD may always show permanent lines — even after being turned off and back on. So, what causes permanent lines in LCDs?

Loose Flex Cable

While permanent lines can appear in LCDs for any number of reasons, one of the most common causes of this phenomenon is a loose flex cable. Flex cables are elastic cables used in the construction of LCDs. Most LCDs feature a main flex cable that connects the actual LCD panel to the main circuit board. And while flex cables are designed to flex without breaking, they aren’t immune to failure.

Laptop computers, for example, use flex cables between the LCD and keyboard. Each time you open and close a laptop, this flex cable is exposed to a little more stress. Eventually, the constant stress may cause the flex cable to loosen, at which point you may notice permanent lines on the LCD.

Dirt or Debris

Something as simple as the presence of dirt or debris can cause permanent lines in LCDs. Assuming it’s well made, dirt or debris shouldn’t be able to breach an LCD’s outer shell. Cheap, low-quality LCDs, however, offer minimal protection against the intrusion of dirt and debris. If environmental pollutants such as this are able to enter your LCD, it could result in permanent lines being displayed.

Resolution Setting

The wrong resolution setting can cause permanent lines in LCDs. If you noticed the permanent lines shortly after changing your LCD’s display resolution, try changing it back to the previous resolution setting.

Faulty T-Con Board

Finally, a faulty t-con board can cause permanent lines in LCDs. Of course, the t-con board is responsible for controlling the logic signal. Also known as simply as the controller board, it’s arguably one of the most important components of an LCD. If the t-con board fails, it can lead to a variety of problems, one of which being permanent lines.

LCD has become the world’s leading display technology. From computer monitors and TVs to smartphones, tablets and more, countless display devices are now powered by LCD technology. Some of these devices, however, may show permanent lines — a phenomenon that’s typically caused by one of the aforementioned problems.