lcd screen dark spot made in china

• Perform highly diversified duties to install and maintain electrical apparatus on production machines and any other facility equipment (Screen Print, Punch Press, Steel Rule Die, Automated Machines, Turret, Laser Cutting Machines, etc.).

Great fix - I was just about to bin my meter when I googled this. Followed the instructions, used UHU glue instead of a glue gun, now the display is perfect - many thanks! Pity I didn"t take a before pic but there was a big black oval covering most of the screen.

One of today’s modern technological wonders is the flat-panel liquid crystal display (LCD) screen, which is the key component we find inside televisions, computer monitors, smartphones, and an ever-proliferating range of gadgets that display information electronically.What most people don’t realize is how complex and sophisticated the manufacturing process is. The entire world’s supply is made within two time zones in East Asia. Unless, of course, the factory proposed by Foxconn for Wisconsin actually gets built.

Liquid crystal display (LCD) screens are manufactured by assembling a sandwich of two thin sheets of glass.On one of the sheets are transistor “cells” formed by first depositing a layer of indium tin oxide (ITO), an unusual metal alloy that you can actually see through.That’s how you can get electrical signals to the middle of a screen.Then you deposit a layer of silicon, followed by a process that builds millions of precisely shaped transistor parts.This patterning step is repeated to build up tiny little cells, one for each dot (known as a pixel) on the screen.Each step has to be precisely aligned to the previous one within a few microns.Remember, the average human hair is 40 microns in diameter.

For the sake of efficiency, you would like to make as many panels on a sheet as possible, within the practical limitations of how big a sheet you can handle at a time.The first modern LCD Fabs built in the early 1990s made sheets the size of a single notebook computer screen, and the size grew over time. A Gen 5 sheet, from around 2003, is 1100 x 1300 mm, while a Gen 10.5 sheet is 2940 x 3370 mm (9.6 x 11 ft).The sheets of glass are only 0.5 - 0.7 mm thick or sometimes even thinner, so as you can imagine they are extremely fragile and can really only be handled by robots.The Hefei Gen 10.5 fab is designed to produce the panels for either eight 65 inch or six 75 inch TVs on a single mother glass.If you wanted to make 110 inch TVs, you could make two of them at a time.

The fab is enormous, 1.3 km from one end to the other, divided into three large buildings connected by bridges.LCD fabs are multi-story affairs.The main equipment floor is sandwiched between a ground floor that is filled with chemical pipelines, power distribution, and air handling equipment, and a third floor that also has a lot of air handling and other mechanical equipment.The main equipment floor has to provide a very stable environment with no vibrations, so an LCD fab typically uses far more structural steel in its construction than a typical skyscraper.I visited a Gen 5 fab in Taiwan in 2003, and the plant manager there told me they used three times as much structural steel as Taipei 101, which was the world’s tallest building from 2004- 2010.Since the equipment floor is usually one or two stories up, there are large loading docks on the outside of the building.When they bring the manufacturing equipment in, they load it onto a platform and hoist it with a crane on the outside of the building.That’s one way to recognize an LCD fab from the outside – loading docks on high floors that just open to the outdoors.

LCD fabs have to maintain strict standards of cleanliness inside.Any dust particles in the air could cause defects in the finished displays – tiny dark spots or uneven intensities on your screen.That means the air is passed through elaborate filtration systems and pushed downwards from the ceiling constantly.Workers have to wear special clean room protective clothing and scrub before entering to minimize dust particles or other contamination.People are the largest source of particles, from shedding dead skin cells, dust from cosmetic powders, or smoke particles exhaled from the lungs of workers who smoke.Clean rooms are rated by the number of particles per cubic meter of air.A class 100 cleanroom has less than 100 particles less than 0.3 microns in diameter per cubic meter of air, Class 10 has less than 10 particles, and so on. Fab 9 has hundeds of thousands of square meters of Class 100 cleanroom, and many critical areas like photolithography are Class 10.In comparison, the air in Harvard Square in Cambridge, MA is roughly Class 8,000,000, and probably gets substantially worse when an MBTA bus passes through.

The Hefei Gen 10.5 is one of the most sophisticated manufacturing plants in the world.On opening day for the fab, BOE shipped panels to Sony, Samsung Electronics, LG Electronics, Vizio, and Haier.So if you have a new 65 or 75-inch TV, there is some chance the LCD panel came from here.

If the LCD is a standard one, 1999 with a few annunciators and a sign, plus decimal points ( and probably a colon between 19 and 99) and has pins and not a zebra strip connection, then you probably can look at RS or other suppliers for a similar LCD display of the same size, as the layout for these is very standard, simply because of the need to have the pins laid out without any vias on the glass. Same height display will very likely fit there, though you might have the odd non original annunciator flag. If it is a Zebra strip version you probably will also find one that size that fits.

I have a DB T20 that is projecting a brown smudge/ spot on the screen. It looks like it’s on the lcd if I look through the front lens. I know can see the lens is fine. What could it be? Is it worth opening it to take a look? Also it makes a buzzing sound like a fan sticking for first minute on power up then works fine.

The most attractive part of your phone is the screen, yet it’s also the most delicate component. This is why it requires special care and attention. Physical damage to your screen mostly takes the form of obvious cracks in the glass, but you may also come across what appears like an ink spot (blot) or bleeding pixels. When the black spot is spreading on your phone screen, you need to have the screen replaced. If you try to repair the phone yourself, you may cause more damage to it, thus complicating the issue.

Hence, seek the help of professionals. Fortunately, Carlcare service center is here to assist you in replacing the damaged screen with an original unit.

Our trained technicians have a great wealth of experience in fixing various issues with a phone’s screen, offering you a flawless screen replacement service best suited to your specific model. Let’s learn more!

When that happens, black and/or blue and purple spots may appear on your screen. If an individual pixel gets damaged, it’ll stay turned off and also appear black.

When more pixels become damaged, the black spots will spread over your phone’s screen like an oil stain. While there are some tips given online on fixing this issue, applying them may do further damage to your device. The best line of action to follow is to seek professional help.

To solve the issue of black spot spreading on your phone’s screen, you need to get the screen replaced. When looking for a screen replacement, here are some factors to take into consideration:

If you’re using a TECNO, Infinix, or itel phone , the best option for repairing the device is the Carlcare Service — the sole authorized service center of these brands. One of the perks Carlcare offers you is that if your smartphone’s warranty is still valid or you have an additional Screen protection plan, you might be able to cut down on the cost of the screen replacement service.

If the black (ink) spot is spreading on the screen of your Infinix, TECNO, or itel phone, simply walk into a Carlcare service center nearby and have it replaced. Join the thousands of customers that love our repair service due to the following benefits we provide for them:

All newly repaired phone screens purchased from Carlcare have a solid warranty of up to 90 days. The meaning of this is that if the screen has any defect within that warranty period, we’ll fix it for you for free.

This is another reason why you should use Carlcare repair service for your phone screen replacement. On our website or via the Carlcare app, you can check the cost of a screen replacement service for popular Infinix, TECNO, and Itel models, including iPhone and other phone brands as well. Simply visit the Carlcare official website, scroll up, and place the icon on Check.

Alternatively, launch the Carlcare app, then press Price to know the price details. By doing so, you can have an idea of how much to budget for screen replacement. However, note that the prices you’ll see are not fixed.

Broken screen replacement service is provided from thousands of repairs stores and phone parts wholesalers worldwide, iPhone of which are mostly engaged in. So how to purchase reliable LCD screens among so many quality grades from China suppliers? Let me firstly elaborate on the quality grades of the iPhone LCD digitizer assembly that most repair stores and traders used to replace the broken ones.

According to the investigation, 90% of the Chinese iPhone LCD screen suppliers are found selling third-party manufactured screens and seldom sell genuine original LCD screens. Therefore, if your phone screen is broken, there would be a high chance for your screen to be replaced with a non-original one. Why? Maybe the cost and quality are relatively competitive, so why not?

As known, Foxconn is authorized to assemble iPhone, so there are some original iPhone LCD screens leaked from the assemble factory. And there are brought out from the factory for replacement. However the price is definitely high and still, some people care more about the quality of the screen than how much they cost, so for this group of customers, the Original Quality of LCD digitizer assemblies are preferred.

For some LCD digitizers, the LCDs are still working while the front glasses are broken, which can be recycled. Some factories recycled these broken screens by removing the broken front glass and attach a new one, then the LCD digitizer assembly would be new again, which is what called refurbished. Brand new original LCD screens are limited, and the refurbished ones can replenish the shortage of the new original LCD digitizer assemblies, for their quality would be more stable than the third-party manufactured.

Some Chinese factories purchase the original single LCD display, not compete LCD screen from the original factory, and then attach high copy front glass, backlight, etc, materials into a complete LCD screen, which quality is not stable and the display color is slightly different from the ones with high copy backlight. Well, their price would be cheaper and loved by many repair shops and wholesalers.

Under the shortage of original LCD screens, many Chinese factories begin to produce the high copy LCD screen. The stock and supply are getting less and less since about 2015, which leads the price goes higher and higher. Therefore the Chinese manufacturer starts to produce LCD screens with high copy raw materials. With competitive prices and good quality that meet most iPhone users’ needs, they are also popular among many wholesalers and repair shops.

With the premium quality of LCD and OLED screens tested strictly, we’ve helped many clients enlarge their markets worldwide. If you wholesale the LCD digitizer assembly or retail them in your repair shop, more information and sample are supported for your reference, please do not hesitate to contact us or leave your comment to discuss more.

Ever had your TV showing nothing but a black screen even if the audio was working? Unfortunately, that’s a common issue with low/middle-end LCD/LED TVs these days… Even more frustrating, this issue often comes from a rather tiny and cheap component that can be easily replaced. Most common issues are:

The first step into repair is to find the root cause of the issue. As backlight failure is a very common issue, this is the first thing to test. To do so, the easiest way is to power on your screen, put a flashlight very close to it and check if you can see the image through. The image would be very dark, like turning the brightness of the screen very very low.

That implies disassembling the TV to access the backlight which is between the LCD screen in the front and the boards in the rear. In my case, with a Samsung F5000, I had to process as follows:

First we have to remove the back housing to reveal the boards (from left to right: main board, T-CON, power supply) and disconnect the LCD panel from the T-CON board.

Note: Older TVs have neon tubes for backlight, which is thicker and less exposed to this kind of failure. LED backlight is the most common thing these days, but do not mistake an LED TV with an OLED TV. The first one is a classic LCD panel with a LED backlight, whereas the second is an OLED panel that doesn’t need any backlight as it is integrated in each pixels (making the spare parts much more expensive by the way).

As we can see, the backlight system is made of 5 LED strips. First thing to do is look for burnt LEDs. Most LED backlight systems have strips set in series, meaning that if one of the them fails, all the system goes dark…

For starters I’ll go with the third one, just to make sure there is no other issues with the TV, but afterwards it’s better to replace the LED with a new one, otherwise you might notice a darker spot on the image.

There might be a lot of other root causes for similar symptoms, a black screen often looks like something very serious and therefore expensive to repair, but this case is the perfect example that taking some time to look for the root cause can sometime lead to a good surprise: here a 1$ fix!

CTL display products are manufactured to rigorous standards. Our display products are consistently recognized as among the highest quality display products in the industry. Nevertheless, due to the nature of LCD technology, an LCD display may exhibit a small number of very small bright or dark spots on the screen. Often, these spots are noticeable only when the screen continuously displays a certain solid color such as an all-white or all black background. This type of background can be present when initially turning a computer on, or when a computer switches the display to a specific screen-saver.

Occasionally, these spots can seem to appear when a user switches to a different desktop background image. In actuality, these spots are pixels or sub-pixels that are stuck always on (viewable as a bright spot on a dark background) or always off (viewable as a dark spot on a light background).

An LCD display is made up of tens of thousands of individual pixels, and each pixel is made up of 3 individual sub-pixels (red, blue and green). In-fact, a 17" LCD has over 1,300,000 pixels and almost 4 million sub-pixels! Each sub-pixel is controlled by an individual transistor which turns the individual sub-pixel that it controls either on or off to create the image on your screen. An anomaly occurring during the manufacturing process can cause an individual transistor to continuously light or fail to light an individual pixel element, causing one of these small spots on the screen. Although this anomaly occurs relatively rarely in individual transistors, there are millions of sub-pixels on each LCD screen, and it is not uncommon for an LCD screen from any manufacturer to contain a few of these transistor anomalies and their associated bright or dark spots. For a manufacturer to sell only LCD""s with no transistor anomalies would result in a prohibitive cost to you, the consumer…one many times higher than it is today. Most people and applications are tolerant of a small number of these transistor anomalies on an LCD screen, and prefer the lower cost of LCD""s that existing standards allow.

CTL sets simple & strict limits as to the allowable number of non-performing pixels or sub-pixels on our LCD display and laptop computer screens. These criteria supplement our existing Warranty and are applicable during the warranty period for all CTL and 2go LCD displays as follows:

The LCD display of products under warranty will be replaced if CTL determines that it has 6 or more bright sub-pixels, 6 or more dark sub-pixels or a combination of 6 or more bright and dark sub pixels.

CTL offers on certain models a No Dead Pixel Warranty.  A monitor purchased with this warranty will be replaced in the warranty period if one (1) or more dark or bight pixels are found.

► When the leading Korean players Samsung Display and LG Display exit LCD production, BOE will be the most significant player in the LCD market. Though OLED can replace the LCD, it will take years for it to be fully replaced.

When mainstream consumer electronics brands choose their device panels, the top three choices are Samsung Display, LG Display (LGD) and BOE (000725:SZ) – the first two from Korea and the third from China. From liquid-crystal displays (LCD) to active-matrix organic light-emitting diode (AMOLED), display panel technology has been upgrading with bigger screen products.

From the early 1990s, LCDs appeared and replaced cathode-ray tube (CRT) screens, which enabled lighter and thinner display devices. Japanese electronics companies like JDI pioneered the panel technology upgrade while Samsung Display and LGD were nobodies in the field. Every technology upgrade or revolution is a chance for new players to disrupt the old paradigm.

The landscape was changed in 2001 when Korean players firstly made a breakthrough in the Gen 5 panel technology – the later the generation, the bigger the panel size. A large panel size allows display manufacturers to cut more display screens from one panel and create bigger-screen products. "The bigger the better" is a motto for panel makers as the cost can be controlled better and they can offer bigger-size products to satisfy the burgeoning middle-class" needs.

LCD panel makers have been striving to realize bigger-size products in the past four decades. The technology breakthrough of Gen 5 in 2002 made big-screen LCD TV available and it sent Samsung Display and LGD to the front row, squeezing the market share of Japanese panel makers.

The throne chair of LCD passed from Japanese companies to Korean enterprises – and now Chinese players are clinching it, replacing the Koreans. After twenty years of development, Chinese panel makers have mastered LCD panel technology and actively engage in large panel R&D projects. Mass production created a supply surplus that led to drops in LCD price. In May 2020, Samsung Display announced that it would shut down all LCD fabs in China and Korea but concentrate on quantum dot LCD (Samsung calls it QLED) production; LGD stated that it would close LCD TV panel fabs in Korea and focus on organic LED (OLED). Their retreats left BOE and China Stars to digest the LCD market share.

Consumer preference has been changing during the Korean fab"s recession: Bigger-or-not is fine but better image quality ranks first. While LCD needs the backlight to show colors and substrates for the liquid crystal layer, OLED enables lighter and flexible screens (curvy or foldable), higher resolution and improved color display. It itself can emit lights – no backlight or liquid layer is needed. With the above advantages, OLED has been replacing the less-profitable LCD screens.

Samsung Display has been the major screen supplier for high-end consumer electronics, like its own flagship cell phone products and Apple"s iPhone series. LGD dominated the large OLED TV market as it is the one that handles large-size OLED mass production. To further understand Korean panel makers" monopolizing position, it is worth mentioning fine metal mask (FMM), a critical part of the OLED RGB evaporation process – a process in OLED mass production that significantly affects the yield rate.

Presently, Chinese panel fabs are investing heavily in OLED production while betting on QLED. BOE has four Gen 6 OLED product lines, four Gen 8.5 and one Gen 10.5 LCD lines; China Star, controlled by the major appliance titan TCL, has invested two Gen 6 OLED fabs and four large-size LCD product lines.

Remembering the last "regime change" that occurred in 2005 when Korean fabs overtook Japanese" place in the LCD market, the new phase of panel technology changed the outlook of the industry. Now, OLED or QLED could mark the perfect time for us to expect landscape change.

After Samsung Display and LGD ceding from LCD TV productions, the vacant market share will be digested by BOE, China Star and other LCD makers. Indeed, OLED and QLED have the potential to take over the LCD market in the future, but the process may take more than a decade. Korean companies took ten years from panel fab"s research on OLED to mass production of small- and medium-size OLED electronics. Yet, LCD screen cell phones are still available in the market.

LCD will not disappear until OLED/QLED"s cost control can compete with it. The low- to middle-end panel market still prefers cheap LCD devices and consumers are satisfied with LCD products – thicker but cheaper. BOE has been the largest TV panel maker since 2019. As estimated by Informa, BOE and China Star will hold a duopoly on the flat panel display market.

BOE"s performance seems to have ridden on a roller coaster ride in the past several years. Large-size panel mass production like Gen 8.5 and Gen 10.5 fabs helped BOE recognize the first place in production volume. On the other side, expanded large-size panel factories and expenses of OLED product lines are costly: BOE planned to spend CNY 176.24 billion (USD 25.92 billion) – more than Tibet"s 2019 GDP CNY 169.78 billion – on Chengdu and Mianyang"s Gen 6 AMOLED lines and Hefei and Wuhan"s Gen 10.5 LCD lines.

Except for making large-size TVs, bigger panels can cut out more display screens for smaller devices like laptops and cell phones, which are more profitable than TV products. On its first-half earnings concall, BOE said that it is shifting its production focus to cell phone and laptop products as they are more profitable than TV products. TV, IT and cell phone products counted for 30%, 44% and 33% of its productions respectively and the recent rising TV price may lead to an increased portion of TV products in the short term.

Except for outdoor large screens, TV is another driver that pushes panel makers to research on how to make bigger and bigger screens. A research done by CHEARI showed that Chinese TV sales dropped by 10.6% to CNY 128.2 billion from 2018 to 2019. Large-size TV sales increased as a total but the unit price decreased; high-end products like laser TV and OLED TV saw a strong growth of 131.2% and 34.1%, respectively.

The demand for different products may vary as lifestyles change and panel fabs need to make on-time judgments and respond to the change. For instance, the coming Olympics is a new driving factor to boost TV sales; "smart city" projects around the world will need more screens for data visualization; people will own more screens and better screens when life quality improves. Flexible screens, cost-efficient production process, accessible materials, changing market and all these problems are indeed the next opportunity for the industry.