As connectivity has become increasingly important in today’s world, the proliferation of laptop computers has grown. Rising hand in hand with this growth, however, has been the money spent on computer repair. As such, more and more individuals are opting to make smaller fixes and upgrades on their own, thus saving themselves repair shop down time as well as the sometimes high cost of a professional.
One of the most frequently replaced parts of a laptop computer is its LCD display. As these displays vary greatly in the sharpness and quality of the image on screen, it pays to first understand the screen itself, along with different display levels and image ratings. Armed with this knowledge, the savvy computer user is ready to visit eBay and buy the LCD panel that best fits their needs. After a review of LCD panel installation basics, buyers can feel confident in their ability to find the right product and replace their own screen.
The Liquid Crystal Display
A liquid crystal display, or LCD, uses liquid crystals to modulate light. An LCD may be a flat panel display, video display, or electronic visual display. It should be noted that the crystals themselves do not emit light but are rather acted upon to regulate it. Amongst the more common uses of LCDs are televisions, computer monitors and laptop screens, smartphone displays, instrument panels, signage, and cockpit displays. An LCD screen is both lightweight and thin.
Five layers comprise the LCD panel . Beneath the front polarised sheet of glass is a grid layer of responsive liquid crystal solution, a mask of coloured pixels, a second sheet of polarised glass, and a backlight. Images are created through manipulating the orientation of the crystals. Serving as a shutter of sorts, varying degrees and voltages of electrical charges open and close in response to these crystals, thus illuminating the screen with degrees of light.
Two techniques used for producing colour are passive and active matrix screens. The older of the two, passive matrix screens activate the LCD grid through the use of two transistors, one for each row and one for each column. Conversely, with active matrix screens, there is a transistor for each point on the grid. Not only does this enable activation of only the desired pixels, it ultimately delivers a higher level of image quality. Most modern LCD displays utilise active matrix technology.
Laptop Screen and LCD Panel Terminology
Without a quality display, a computer’s hardware, software, memory, processor, and other features fade in importance. The same applies to televisions, tablets, and smartphones, as the display is the face of these devices. To adequately understand LCD displays, users should familiarise themselves with a handful of terms, including black level, contrast ratio, gamut, and uniformity.
All displays are presented in gradients of shades; the better the quality of the screen, the more seamless the image appears. More often than not, though, some degree of banding is apparent; the trick is to find a comfortable level of smoothness and affordability.
The lower the black level, the darker and purer the black is. This is an important factor when considering video playback on a screen, as dark images appear muddy and ill-defined when the black level is too high.
White level ratings are reversed, as higher numbers mean a bright white display. To remember these distinctions, consider RGB colour levels on Photoshop images. When these factors are 0, the resulting colour is black; conversely, a level of 255 is pure white.
The gamut of colours a computer display should be able to reproduce is the standard colour space, or sRGB. Of note, though, is that most screens are only capable of 75 per cent sRGB. Even mid-range displays achieve a 90 per cent rating. Only the top-tier laptop screens can represent the full specified gamut.
On a display, the ratio of luminance between the darkest colour (black) and lightest colour (white) is known as the contrast ratio. The higher the contrast ratio, the more defined and realistic its images appear. This does not, however, mean that an extensive trail of zeroes equates to a superior display. Rather, as there is no standardised test to determine contrast ratios, those listed on the package may not necessarily reflect a better display. Instead of relying on the box, it is best to obtain contrast ratio information from side-by-side product reviews, which use the same criteria to measure all models.
In its simplest terms, dithering is a technique that creates colours through a combination of hues when the display itself is not capable of producing the actual colour. As one might expect, results are not always ideal. In some cases, LCD displays use dithering as a means to soften banding; however, even this can lead to less desirable shimmering blacks that come off as flat and lifeless.
A visible gap between pixels creates dot pitch, also known as the screen-door effect. A lower dot pitch translates into less of a gap between pixels, and is thus preferable. Of course, dot pitch becomes somewhat relative depending on the size and position of the display. Overall, the further a viewer is from a screen, the less noticeable the space between pixels.
LCD technology is not reserved for LCD panels; rather, it is in use on nearly all computer screens being sold today. The trouble is that light must project uniformly through an LCD panel for it to display images correctly, which would require the panel itself to emit luminance. This issue does not apply to OLED and plasma screens, as they create their own light.
Without brightness, the display on a mobile device, such as an iPad, would be virtually useless. Sources of light are measured in units of luminance, or nits. The higher the nit rating, the brighter the laptop’s display is. On average, laptops and mobile devices have anywhere from 200 to 300 nits. Over 300 nits is preferable, and over 500 especially good. Comparatively, television displays have in excess of 1,000 nits.
Laptop Screens: Installation Basics
Prior to installation, there must be uninstallation. In truth, removing the old laptop screen is the hardest part of installing a new one. It is important to read the instructions and take one’s time with this task to ensure full functionality when the laptop computer is put back together. Videos abound on the internet and can be handy resources when needed.
LCD Panel Removal
Prior to attempting to replace a laptop screen, users should unplug the computer and remove its battery. Next, with the laptop open, remove all rubber or plastic screw covers and, beneath them, the screws from the plastic frame, or bezel . Note that there may be additional screws framing the monitor, in which case these need to be removed, as well. To ensure easy replacement, it is a best practice to line up the screws in order of removal.
The bezel is responsible for holding the LCD panel in place. A computer user should take care in removing this part, as it is somewhat fragile. The bezel can be removed by lifting the plastic away from the screen. While some people prefer to start on the left of the screen, it is easier on some laptops to begin at the bottom. Continue to pry until the bezel snaps out from the screen mounting, making sure there are no cables attached. If the bezel does not come out easily, either screws remain or the bezel is attached with glue; in the latter case, an X-Acto blade can be used to carefully pry off the bezel.
The LCD panel is held in place by small screws, each of which must be removed. In most cases, there are four screws on each side, although the installer should always check for more. Once it is free of the laptop, the screen can be tilted and laid flat on the keyboard, being careful not to strain any webcam, microphone, or Wi-Fi cables.
Next, the video and inverter connectors must be disconnected. As the video connector is very delicate, installers should take their time with this step. The connector is removed by squeezing on the tabs on either side and pulling it gently away from the circuit board . Removing the inverter connector is a bit trickier and can vary from laptop to laptop; as such, manufacturer instructions should be consulted before performing this step. When complete, the old laptop screen can be removed and recycled.
LCD Panel Installation
The first step in installing a new laptop screen is removing the protective film from the replacement screen. Next up, it is time to reconnect the connectors, first the video cable and then the inverter connector . Neither of these tasks requires much force although it is worth double checking that the connections are properly aligned.
After being aligned with the laptop frame, the LCD panel should be secured, starting with the top left screw. As with the install, make sure all cables are appropriately tucked away. Replace the remaining mounting screws on both sides. Next, working bottom to top, snap the bezel back into place. Replace the screws in the order they were removed and then top them off with the plastic or rubber screw covers, as required. The use of adhesive may be required to ensure a proper fit. After reinstalling the battery, the laptop can be powered up. When the start-up graphics appear on screen, the project can be deemed a success.
How to Buy LCD Panels on eBay
By now, you have gained an understanding of how laptop screens display images, including variations in black levels, colour space, contrast ratio, and dot pitch. You have reviewed options for your particular laptop model and are aware of both your current screen’s capabilities and what you are looking for in a replacement panel. On eBay, you can find LCD panels to meet every need, whether you are seeking a 10-inch or 15.5-inch screen, an Aspire or a Dell, a screen with or without a bezel . You may also choose to protect your new investment with a screen protector, yet another product you can find in abundance on eBay.
Whether you sort results by price, condition, or distance, or even allow eBay to display the results it finds to be the best matches for your search terms, you can easily review photos, prices, and descriptions of the products for sale. Remember to factor in the price of shipping when comparing costs and be aware of the seller’s return policy.
Tinkering with laptop computers is not as scary as it used to be. These days, even non-techies are making simple repairs themselves, such as adding memory, swapping video cards, or replacing batteries. Another thing users may want to tackle on their own is replacing the LCD panel. Whether their old screen is scratched or cracked or its images are visually flawed, by following a few simple steps, computer users can swap their old LCD panel for a new one in just a matter of minutes.
It pays to first obtain a basic understanding of LCD screens, including contrast ratio, banding, uniformity, and gamut, and to recognise how these ratings and numbers affect what is shown on the screen. eBay has a broad range of LCD panels for sale, giving the savvy shopper a number of products from which to choose. There, computer users are sure to find just the laptop screen they are looking for.