How to Fix a Stuck Pixel on an LCD Monitor

If your LCD screen has a stuck or dead pixel (a point on the screen that is always lit or always dark), it is usually due to a transistor malfunction or uneven distribution of liquid in the liquid crystal display (TFT LCD). This can often be fixed.

Steps....

Software Method

1. Try running pixel fixing software (see Sources and Citations). Stuck pixels can often be re-energized by rapidly turning them on and off. If this fails, complete the following steps.

Pressure Method

1. Turn off your computer's monitor.
2. Get yourself a damp washcloth, so that you don't scratch your screen.
3. Take a household pen, pencil, screwdriver, or some other sort of instrument with a focused, but relatively dull, point. A very good tool would be a PDA stylus.
4. Fold the washcloth to make sure you don't accidentally puncture it and scratch the screen.
5. Apply pressure through the folded washcloth with the instrument to exactly where the stuck pixel is. Try not to put pressure anywhere else, as this may make more stuck pixels.
6. While applying pressure, turn on your computer and screen.
7. Remove pressure and the stuck pixel should be gone. This works as the liquid in the liquid crystal has not spread into each little pixel. This liquid is used with the backlight on your monitor, allowing different amounts of light through, which creates the different colors.

Tapping Method

1. Turn on the computer and LCD screen.
2. Display a black image, which will show the stuck pixel very clearly against the background. (It is very important that you are showing a black image and not just a blank signal, as you need the backlighting of the LCD to be illuminating the back of the panel).
3. Find a pen with a rounded end. A Sharpie marker with the cap on should be fine for this.
4. Use the rounded end of the pen to gently tap where the stuck pixel is - not too hard to start with, just enough to see a quick white glow under the point of contact. If you didn't see a white glow, then you didn't tap hard enough, so use just slightly more pressure this time.
5. Start tapping gently. Increase the pressure on the taps gradually for 5-10 taps until the pixel rights itself.
6. Display a white image (an empty text document is good for this) to verify that you haven't accidentally caused more damage than you fixed.

Tips....

• If the pressure and tapping don't work directly on the stuck pixel, start moving outward around the stuck pixel. If you see the pixel flicker while doing this then you know where you can focus the pressure and tapping techniques rather than directly on the pixel.
• Many people report success with this technique but these instructions won't work in every case. It may take a few attempts to make sure you are pressing exactly on the stuck pixel.
• These instructions will fix "stuck" pixels, not "dead" ones. Dead pixels appear black while stuck pixels can be one constant color like red, blue or green.
• An alternative, but similar technique involves gently massaging the stuck pixel with a warm damp (not wet) soft cloth.
• Alternative technique to tapping: Using a rounded pencil eraser, push with moderate pressure into screen at stuck pixel.
• If these instructions don't work, you can hopefully get the monitor replaced through your manufacturer. If your monitor falls under the specifications of replacement, get in contact with the manufacturer to set up replacement plans.
  

Warning....

• Do not attempt to open the monitor as it will void the warranty and the manufacturer will not replace it.
• Make sure you don't get any electrical equipment wet or it may break.
• Some people claim that touching the screen can cause more pixels to become stuck, although this has not been proven.

  

• Sub-Pixel Layers
  LCD Displays are composed of multiple layers. Each layer is separated by ve ry small glass spacers. These spacers and the individual layers are very delicate. Rubbing an LCD panel with a finger or even a cloth can cause the spacers to break and cause further issues beyond the original pixel fault. As such most repair technicians with service certifications are trained not to use the rub or tap methods - use them at your own risk.
• Most LCD manufacturer warranties for LCD displays will cover replacement of the panel when the display reaches a certain number of pixel anomalies. These warranties however generally will not cover damage caused by rubbing the screen so use extreme caution and contact the manufacturer before proceeding to see if you qualify for repair or replacement.

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What is LCD Monitor?

LCD stands for Liquid Crystal Display, referring to the technology behind these popular flat panel monitors. An LCD monitor is distinguishable from a traditional CRT monitor as the latter has a bulky footprint with a depth of several inches and a weight of 30 - 50 pounds (13 - 23 kilograms) or more, while LCDs are commonly 1 - 3 inches (2.5 - 7.5 cm) thick and weigh less than 10 pounds (4.5 k).

LCD displays were used on laptop computers before the technology improved enough to make the jump to desktop monitors. An LCD monitor consists of five layers: a backlight, a sheet of polarized glass, a "mask" of colored pixels, a layer of liquid crystal solution responsive to a wired grid of x, y coordinates, and a second polarized sheet of glass. By manipulating the orientations of crystals through precise electrical charges of varying degrees and voltages, the crystals act like tiny shutters, opening or closing in response to the stimulus, thereby allowing degrees of light that have passed through specific colored pixels to illuminate the screen, creating a picture.

As LCD technology evolves, different techniques for producing color emerge. Active-matrix or TFT (thin film transistor) technology produces color and images as sharp as any CRT and is generally considered superior to passive-matrix technologies.

Important specifications to consider when shopping for an LCD monitor include contrast ratio, brightness (or "nits"), viewing angle, and response time.

Contrast ratio relates to the display's comparative difference between its brightest white values and its darkest black values. A higher contrast ratio will have truer colors with less "wash out." The standard offering for lower end models is commonly 350:1. Many experts recommend a contrast ratio of 500:1 or better.

An LCD monitor is brighter than a CRT, giving the consumer little reason to hunt for an especially bright model. Brightness is measured in nits, or one candela per square meter. Anywhere from 250 - 300 nits is standard. If the nits are much higher you'll likely end up adjusting the brightness way down.

The viewing angle is an especially important consideration if you plan to have multiple people viewing the LCD monitor at any given time. There is a vertical and a horizontal viewing angle specification, which refers to the degree you can stray from dead center before the picture starts to wash out. High contrast levels usually go hand-in-hand with wider viewing angles. Many recommend a viewing angle of at least 140 degrees horizontal and 120 degrees vertical. The wider the viewing angles, the better.

Response time is measured in milliseconds (ms) and refers to how long it takes pixels to turn from completely white to black and back again. Smaller values represent a faster response time and are more desirable, especially for gaming or viewing video. If the response time is slow, "ghosting" or "trailing" can occur with fast-moving images, as repaints of the screen overlap. A maximum response time should be no more than 25ms for general use, and 17ms is better. Many gamers report no ghosting using an LCD monitor with a response time of 16ms or less.

LCDs use only one-third to one-half the electricity of their CRT counterparts. They are much easier on the eyes, take up 90% less space, and only weigh a few pounds. They also emit far less low-frequency radiation than CRTs. This makes LCDs a great choice for nearly everyone, and ideal for people who work all day in front of the screen. Colors may change hue as one moves to the outer limits of the viewing angle, particularly on displays with narrow viewing angles and low contrast ratios. For this reason graphics professionals that require exacting color consistency regardless of viewing angle generally use CRTs, though LCDs have improved in this regard.

An LCD monitor comes in standard sizes from 15-inches to 21-inches, and larger. The viewing screen is the same size as the rated display, unlike CRT monitors. Therefore a 15-inch LCD will have a 15-inch viewing screen.

A potential weak link of an LCD monitor is the backlight. Many monitors come with a 3-year warranty, but stipulate 1 year for the backlight. Models with 3-year warranties that cover the backlight usually cost a little more but may be worth the extra investment.

Reflective twisted nematic liquid crystal display.

1. Polarizing filter film with a vertical axis to polarize light as it enters.
2. Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is turned ON. Vertical ridges etched on the surface are smooth.
3. Twisted nematic liquid crystal.
4. Glass substrate with common electrode film (ITO) with horizontal ridges to line up with the horizontal filter.
5. Polarizing filter film with a horizontal axis to block/pass light.
6. Reflective surface to send light back to viewer. (In a backlit LCD, this layer is replaced with a light source.)

A liquid crystal display (LCD) is an electro-optical amplitude modulator realized as a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector. It is often utilized in battery-powered electronic devices because it uses very small amounts of electric power.

A comprehensive classification of the various types and electro-optical modes of LCDs is provided in the article LCD classification.

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