How to Locate Dead or Stuck Pixels on an LCD Monitor

The Liquid Crystal Display [LCD] technology in a monitor uses a liquid crystal solution between two sheets of polarizing material, which align the crystals when an electric current is passed. Pixels are the vertical and horizontal dots that form the images displayed on an LCD monitor. Each pixel is further divided into three sub-pixels for red, green and blue light. A 1280 x1024 resolution LCD monitor typically has approximately 3.9 million sub-pixels.

A single dust particle that lands on a pixel during manufacturing or a slight jerk during shipping can damage or break a pixel. The LCD panels also include tiny transistors that transmit current to each pixel. If a transistor shorts out, a "dead" pixel is formed. Pixel defects often go unnoticed by consumers, but if you have enough of them you may be eligible for a return or exchange. Here's how to check your monitor for pixel defects.

Difficulty: Moderately Easy

Instructions

1. Find "dead" pixels (pixels permamently in the off mode, with no ability for light or current to pass) by switching on your LCD monitor and displaying a totally white screen. Dead pixels will appear as dark or black spots on the white surface.

2. Find "stuck" pixel (pixels where one or all of the subpixels have failed) by switching on the LCD monitor and displaying a black screen. Any white spots that appear on the black screen indicate a pixel where all three of its red, green and blue sub-pixels have failed. A green, red or blue dot indicates that one of the three sub-pixels has failed.

3. Turn the monitor off, press your finger against a soft, clean cloth and gently place pressure on the area of the screen with a stuck pixel, then turn the monitor back on. You may be able to "massage" away stuck pixels.

4. Look online for free software for Windows called UDPixel, which may be able to fix defective pixels.

5. Read and understand your monitor's exchange policy in regards to faulty pixels. Some companies have fixed guidelines on how many dead or faulty pixels would get you a replacement or a return (usually six to nine faulty pixels). Some companies also have a policy on the location of the faulty pixel on the screen.

Tips & Warnings

• Apple uses the term "pixel anomaly" for the defects in their pixels.