What to look for
- Run black, white, and RGB in the browser to record the mark’s color and location.
- Take a screenshot and view it on another device. A physical pixel fault will not be captured in the screenshot file.
- Connect an external monitor or TV. If the same artifact appears there, investigate the app, operating system, or graphics hardware.
- Restart and inspect the startup, firmware, or preboot diagnostic screen where available.
- Use the laptop maker’s built-in display or hardware diagnostic; it removes the browser and much of the normal software stack from the test.
Use this order
- Clean the panel and remove glare.
- Run the manual colors and mark the location.
- View a screenshot on another display.
- Compare an external monitor, restart screen, or firmware screen.
- Run the manufacturer’s built-in diagnostic and save its result or error code.
- If the mark stays only on the laptop panel, document it for return, warranty, or repair.
Common questions
Why is the dot visible in my screenshot?
That means the dot was part of the rendered image before it reached the physical panel. Check the app, overlay, graphics driver, or GPU rather than treating it as one failed screen pixel.
Can I use a laptop built-in test without Windows or macOS?
Often yes. Dell provides an LCD built-in self-test on supported laptops; Apple Diagnostics runs separately from normal apps. The exact keys and coverage depend on the model.