Help! My Laptop Screen Has a Horizontal Line – What Can I Do?

There are a couple of potential issues to consider: it could be a failing screen or screen cables, or it might be related to a failing GPU. A good way to test this is by connecting your laptop to an external monitor. If the same line shows up there, it's likely a GPU problem, and avoiding a costly repair on an old machine might be best.

Most likely, the horizontal line is just a defect in your LCD screen. If it were a cable issue, you'd probably see random lines instead. A GPU failure might present itself as distorted images or tile-like shapes in display. Unfortunately, if it's the screen that's broken, a replacement might cost more than buying a used laptop nowadays.