Why some LCD pixels stay dark while others light up

One small spot on your screen stays black, even when the rest of the picture changes. It can look like a speck of dust, but if it stays in the same place on every page, a pixel or part of the display may not be working.

An LCD screen uses a backlight and tiny color-filtered parts called subpixels to make each pixel. A problem with one or more subpixels can leave a dark spot while neighboring pixels still show an image. The Display Test can help you see whether the spot changes across solid colors.

Check whether the dark spot follows the screen

1. Open the Display Test on the screen with the dark spot, then use its color test.
2. Look at the spot against several solid colors, including white, red, green, blue, and black. Note whether it stays black or changes color.
3. Check the same area in another app or on a plain background. Move a window over the spot, then move the window away.
4. If possible, take a screenshot and view it on another device. A physical pixel defect will not be part of the screenshot image.

Look closely without pressing the panel. A phone camera or magnifier may help you see whether the spot is one pixel or a larger patch, but camera images can add visual artifacts, so use them only as a guide.

What the result means

The spot stays dark on every color

This points to a pixel or subpixel that is not passing enough backlight to appear lit. If all three color subpixels are affected, the whole pixel can look black. A single dark pixel among otherwise normal pixels does not usually mean the backlight has failed, because nearby areas still light up.

People often call a pixel that stays unlit a dead pixel. Terms are not used consistently, so the appearance matters more than the label. See stuck pixel vs. dead pixel for the common distinction.

The spot changes color or shows one color on some backgrounds

One color subpixel may be stuck or failing while the others still work. The spot can look red, green, blue, or like a mixed color depending on the screen image. A flashing pixel tool is sometimes tried for a pixel that is stuck in a lit state, but it cannot repair a physically damaged LCD. You can try the Stuck Pixel Fixer if you choose, but stop if the flashing is uncomfortable. Read how to protect your eyes during a flashing pixel test first.

A whole line or a larger area is dark

A row, column, or block of dark pixels can point to a panel connection or display driver problem rather than one pixel. If the area grows, flickers, or changes when you gently move the laptop lid, stop testing and arrange a repair. Do not push or twist the panel to see if it changes.

The spot appears in a screenshot viewed elsewhere

If the same mark appears in the screenshot on another device, the mark is likely in the image, app, or software rather than a physical LCD pixel. If it is absent from the screenshot but remains visible on the original screen, the display panel is a stronger possibility. A screen overlay can also imitate a stuck pixel, so check whether a fixed dot is an overlay or a pixel defect.

What you can try safely

1. Clean the screen gently. Turn the display off and use a clean microfiber cloth. A mark on the surface can resemble a dark pixel, but do not scrape it or press hard.
2. Check brightness and display settings. Set a steady, comfortable brightness while comparing colors. In Windows 11, check Settings › System › Display. On macOS, check System Settings › Displays. On an iPhone, check Settings › Display & Brightness; on Android, open Settings › Display, though menu names vary by device. These settings can change how visible a defect looks, but they do not repair a damaged pixel.
3. Restart the device and check another app. This can rule out a temporary graphics or software issue. If the same spot remains in the Display Test and across apps, a display fault becomes more likely.
4. Reconnect an external monitor. If the problem is on an external display, check its cable and try another port or cable. This can rule out a connection issue, though a single fixed pixel usually points to the panel itself.
5. Do not press or rub the spot. Pressure can damage the liquid crystal layers or spread a defect. Avoid home remedies that involve tapping the screen or applying heat.

When the LCD panel may need repair

If the spot stays in the same place on solid colors, is absent from screenshots viewed elsewhere, and remains after a restart, it is probably a physical display issue. A browser test can show how the panel behaves, but it cannot identify the exact failed transistor, subpixel, or panel connection.

Check the manufacturer’s warranty and dead-pixel policy before paying for service. Policies differ, and a single pixel may not qualify for a replacement. On a laptop or phone, compare the repair cost with the price of replacing the device. If the dark area is spreading or a line has appeared, stop using pressure-based fixes and ask a repair shop to inspect the panel.

Why nearby pixels still work

Each LCD pixel is controlled by tiny electronic components, and the panel contains millions of them. A defect can affect one subpixel or a small group without stopping the backlight or the rest of the screen. That is why the image around a dark pixel can look completely normal.

A dark spot that never changes is different from temporary image retention, where a faint outline from an earlier image lingers and may fade. If the mark is faint and changes after the screen shows different content, compare it with screen image retention after gaming.