How to check an LCD TV or monitor for dead pixels.

Answers to the most common TFTTest 1.52 questions

Question: There is a moving square in the matrix performance evaluation test,
but there are only glitches flickering all over the screen. StrIPes.
The indicator in the upper right corner shows 0.00 ms.
The same situation with a colored strIPe running vertically in the next
test section.
Answer: In the settings of the card drivers, you must enable the vertical
synchronization.

Question: When the mode of measuring the speed of the matrix is ​​selected, TFTTest shows 16 ms, and in
the documentation on the monitor is written 25 ms. And who is cheating?
Answer: The program _ CANNOT_ measure the speed of the matrix. 16ms is the refresh time
pictures on the screen, inversely proportional to the frame rate.

Question: After starting the measurement of the matrix speed on some monitors, it remains
light streak.
Answer: Indeed, on monitors made on IPS LG-PhilIPs matrices, it remains
light strIPe. The mechanism of the streak is unknown. In a few
minutes it disappears and does NOT have a negative impact on the monitor.

Question: Why does the program show 50hz 20ms in the matrix speed measurement tests?,
although the card settings are set to 60Hz or 75Hz.
Answer: 50Hz appear when installed in the card settings as a second
PAL TV device. If you put an NTSC TV, then the frequency
update will become 60Hz. And if you disable in the map settings
TV output, the refresh rate will again be 60Hz
or 75Hz. To emphasize again that this is the refresh rate (drawing)
screen. Even when the program shows 50Hz, the sweep frequency
the monitor will still be 60Hz or 75Hz depending on the settings
cards.

Question: Why in tests of measuring the speed of matrices a square “running” on screen
jerk.
Answer: Due to the inconsistency of screen refresh rates and monitor sweep.
For example, when you turn on the PAL TV in the card settings
the screen drawing frequency will be 50Hz, and the output to the monitor via DVI output will be 60Hz.

Question: I choose the mode, but nothing happens.
Answer: the mode changes only at the time of the test when working in full screen mode.

ALGorithm for checking monitors with TFTTest 1.52

Tfttest 1.52 is not just a banal screen fill, but a complex of dough designed to comprehensively test your monitor or TV. You will check all the most fundamental characteristics by which the monitor is actually selected. After you download the latest version of TFTTest 1.52. You can start testing your monitor, if you do not know how to use the TFTTest 1.52 program to identify THESE harmful dead pixels, then below are instructions for using the TFTTest 1.52 program.

Important!

All monitor / TV tests, except for the interpolation check, are preferably carried out at “native” monitor resolution. The bit color is 24 or 32 bits. At 8 and 16 bit colors, color gradient tests will show obvious strIPes NOT related to the resolution of the monitor matrix. The frame rate is used in tests to evaluate the performance of the matrix. It is advisable to set the maximum frequency for this mode and the method of connecting the monitor.

When testing several monitors simultaneously, it is desirable to set the same settings for brightness, contrast and color temperature.

All tests are run in full screen mode in accordance with the selected resolution. Selecting the Default mode uses the current Set Mode.
For Windows 95/98 / ME operating systems, the screen resolution is set separately, the frame rate is separately. However, not all frame rates for a given resolution may be supported by the monitor.

  • Matrix backlight uniformity and absence test “broken points”
  • Interpolation test suite “non-native” permissions
  • Color gradient for checking linearity and resolution of a matrix
  • Colored wedges to check synchronization Increase the brightness of colors
  • Stepped gradient for checking the linearity and discreteness of the matrix
  • Circles for checking interpolation “non-native” permissions
  • Ring gradient for checking the linearity and discreteness of the matrix
  • Interpolation Check Patterns “non-native” permissions
  • Checking font readability
  • Legibility check grid
  • Moving square
  • Moving square with scale grid

1. Test of matrix backlight uniformity and absence “broken points”

2. A set of tests of staggered points, vertical lines and horizontal lines to test interpolation “non-native” permissions. It is recommended that you configure your monitor for each mode before testing. The tests reveal the heterogeneity of the image in the form of horizontal and (or) vertical strIPes, in comparison with the image in “native” The change in the average screen brightness when going from vertical to horizontal lines at native resolution, serves as a qualitative assessment of the channel bandwidth when connected via D-Sub.

3. Color gradient test. The uniformity of the increase in brightness from the upper left corner to the lower right is checked. On matrices with low color resolution, a step-like change in brightness is observed. On a number of matrices, characteristic diagonal strIPes of increased or decreased brightness are observed, due to the nonlinear characteristics of the matrix. At startup, pay attention to the setting of 24 or 32 bit colors.
Changing the direction of the gradient. Up, Down
Color change. Left, Right, LeftMouse click
Brightness change. Plus, Minus
Exit Test. Esc RightMouse click

4. The test is similar to the previous one, but simultaneously displays several horizontal or vertical color wedges. According to the test, the synchronicity is checked, the increase in the brightness of the wedges and the balance of colors.
Mode change. Left, Right, LeftMouse click
Brightness change. Plus, Minus
Exit Test. Esc RightMouse click

5. Gradient color gradient test. The uniformity of the increase in brightness and the resolution of the transition according to the gradation of brightness are checked. When starting, pay attention to the setting of 24 or 32 bit colors.
Mode change. Left, Right, LeftMouse click
Exit Test. Esc RightMouse click

6. Test concentric circles to test interpolation “non-native” permissions. It is recommended that you perform a monitor setup for each mode before testing. Tests reveal the heterogeneity of the image by comparison with the image in “native” permission.
Mode change. Left, Right, LeftMouse click
Exit Test. Esc RightMouse click

7. Color gradient test. The uniformity of the increase in brightness along the radius of the circle is checked. On matrices with low color resolution, a step-like change in brightness is observed. At startup, pay attention to the setting of 24 or 32 bit colors.
Changing the direction of the gradient. Up, Down
Change color. Left, Right, LeftMouse click
Brightness change. Plus, Minus
Exit Test. Esc RightMouse click

8. A set of patterns for checking interpolation “non-native” permissions. It is recommended that you perform a monitor setup for each mode before testing. The tests reveal the heterogeneity of the image in the form of horizontal and (or) vertical strIPes, in comparison with the image in “native” permission.
Mode change. Left, Right, LeftMouse click
Exit Test. Esc RightMouse click

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9. Test to check the readability of fonts of various sizes and weights at “relatives” and “non-native” Resolution.
Change fonts. Left, Right, LeftMouse click
Brightness change. Plus, Minus
Exit Test. Esc RightMouse click

10. Test for checking blurring and line thickness. Like the previous test, it characterizes the readability of fonts and small details.
Mode change. Left, Right, LeftMouse click
Brightness change. Plus, Minus
Exit Test. Esc RightMouse click

11. Test for visual assessment of the matrix performance. Most visual when simultaneously testing several monitors on matrices of different types, and when compared with CRT monitors. Parameters for comparison. brightness of the moving square, length tail, blur border, color and geometry of the square.
Information in the upper left corner of the screen:
Cur 1280×1024 32 bit 60 hz. Current mode
60hz 16.6ms. Screen refresh rate and interval
Vh = 5 p / s Vv = 5 p / s. Square shift speed (dots / frame)
Speed ​​change. Up, Down
Brightness change. Plus, Minus
Exit Test. Esc RightMouse click

12. The test is similar to the previous one, but the square moves horizontally or vertically, and a scaled grid is drawn.
Speed ​​change. Up, Down
Mode change. Left, Right, LeftMouse click
Brightness change. Plus, Minus
Exit Test. Esc RightMouse click

Tools for testing LCD TVs and monitors.

To begin with, you need to write down the necessary software package, which includes it, on a USB flash drive. Archive with color fills and gradients with a resolution of 1920×1080 and the TFTTest program. It is also very useful to have with you a set of tests with which you can demonstrate to the client the capabilities of his TV. 3D support, quality of rendering of dynamic scenes (100, 200, 400, 800 Hz) sound quality, the ability of the player built into the TV to play one or another format.

1. Download the fill for checking TVs, you can follow one and the links:

  • Download fills for checking 1080P TVs. For checking TVs with a resolution of FullHD 1920 x 1080 pixels.
  • Download without waiting.

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  • Download fills for testing 720P TVs, for testing TVs with HDReady 1366×768 pixels.
  • Download without waiting.

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2. Download the TFTTest program for checking monitors for dead pixels, you can go through one and the links:

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With the TFTTest program, you can also check the TV for dead pixels, but for this you have to connect a laptop or computer to the TV.

3. Downloads to check the TV or monitor for dead pixels. Rollers are sequentially displayed fills of different colors, gradients and tables. There is also sound in thes, so you can immediately check the performance of the speaker system. The archive contains two files. For testing TVs with FullHD (1920×1080) and HDReady (1280×720) resolution

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4. Download the DeadPixelTester program. The Dead Pixel Tester utility was created specifically for testing LCD screens for dead pixels. Allows you to highlight any areas of the screen with any of the selected colors to identify malfunctioning cells. To do this, just select the desired color and check its display on the entire area of ​​the monitor surface. If a discrepancy is found, there is a special window (with five primary colors) for a more detailed study. Below you can read the instructions for DeadPixelTester.

  • Download DeadPixelTester
  • Download without waiting.

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ALGorithm for checking TVs (briefly)

A brief descrIPtion of how to check the TV using previously downloaded fillings. “hot”, “dead” (They are broken) pixels we use monophonic fills, we focus (of sight) and carefully peer at the screen, it is especially difficult to notice “dead” pixel because It is not visible in every color. It is more difficult to identify “dependent” pixels, fill is used to identify them “chess grid” or “grid” (She’s moire)

Moire and focusing. Filling the screen with intricate details, small text or ornamentation determines whether the screen provides a clear image of various small details. Another test can catch the presence of moiré. unpleasant effects with a shadow, which blur image, deprive the picture of brightness and clarity.

Everything for equIPment sellers. Instructions for working with the program Dead pixel tester

Basic princIPles:
1) Make sure your screen is free of dirt and fingerprints, if possible, clean it with a dedicated product.
2) Make sure your screen resolution for your monitor is set correctly, for example if your screen is 1680×1050, Make sure your monitor resolution is set to 1680×1050.
3) Use the right mouse button to switch to the main menu on and off, so you can see the whole screen without any interference.
4) Use the left mouse button to switch between the primary colors and the fill black (check for dead pixels), blue (check for dead blue pixels), red (check for dead red pixels), green (check for dead green pixels). White (check for dead pixel group)
5) Every time you choose a new color, carefully examine the screen looking for defects (black dots. Dead pixels will be visible on the screen of any color)
6) Use [M] to turn on a marker on any suspicious points on the screen. This allows you to inspect the rest of the screen and return to that area / Check if the screen is blank.

[X] in the upper right corner of the screen hides the Program dialog box, you can also use the right mouse button or [ESC]
Left Mouse Button: Scrolls through the primary colors red, green, blue, black and white
Clicking the scroll wheel: Turns the mouse cursor on and off, the scroll wheel changes the display view
Right mouse button: Shows and hides the main menu
Pattern selection: Switch between on-screen color and different patterns (e.g. gradients).
Markers: press the [M] button and a small circle will be drawn at this point. This allows you to further examine the screen for the presence of dead pixels a, and then return to the marked areas. You can remove a marker by simply placing the mouse back in this position and press [M] again, or use [R] to remove all markers on the screen.
Auto Cycle: automatic cycles of color change, without clicking the mouse. Alongside, you can change the speed at which it happens in milliseconds (1000ms = 1 second)
Main color: shows the currently selected color
Pattern color: shows the secondary colors that you have selected (use the right mouse button to switch)
Information: Basic information about your current screen resolution.

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TV Matrix Test

A little about dead pixels!

It is not uncommon for LCD, LED and even OLED TVs to have defects such as Broken Pixel. It usually looks like a point in an arbitrary area of ​​the screen, of any color.
There are 4 types dead pixels:

Dead pixels are pixels that are off (always off). On a white background, it looks like a black dot.

Hot pixels. on the contrary, they are always on and on a black background they look like a white point.

Stuck pixels may glow red, blue, green or yellow. This is because some of the subpixels are always on or always off.

A group of defective pixels. These are several defective pixels in a 5×5 pixel square.

(Click on the image for a larger GoPro view)

Checking with a USB stick

Using the image data, you can check your TV for manufacturing defects such as:

  • Defective pixels;
  • Matrix highlights;
  • Uneven backlighting;

Use the built-in media player to scroll through all the pictures. the matrix defect will be noticed a lot.!

If there is a broken pixel, you will definitely see it as a black, white or colored point in any area of ​​the screen.

Follow the link to DOWNLOAD THE ARCHIVE (28 test images), unpack it onto a flash card and insert it into the USB port of your TV!

Checking with a Laptop

You can also use a special program to test the TV screen or monitor

This program allows you to evaluate Not only the presence or absence of dead pixels on the display, but also the uniformity of the matrix backlight, geometric distortion and response time of the matrix.

You can download the program for checking the TV screen for broken piskels at the link: DOWNLOAD

Verification with a professional

You can Call the wizard to set up your TV. As well as checking the screen of your TV or monitor for dead pixels!

A little about dead pixels!

It is not uncommon for LCD, LED and even OLED TVs to have defects such as Broken Pixel. It usually looks like a point in an arbitrary area of ​​the screen, of any color.
There are 4 types dead pixels:

Dead pixels are pixels that are off (always off). On a white background, it looks like a black dot.

Hot pixels. on the contrary, they are always on and on a black background they look like a white point.

Stuck pixels may glow red, blue, green or yellow. This is because some of the subpixels are always on or always off.

A group of defective pixels. These are several defective pixels in a 5×5 pixel square.

(Click on the image for a larger GoPro view)

Checking with a USB stick

Using the image data, you can check your TV for manufacturing defects such as:

  • Defective pixels;
  • Matrix highlights;
  • Uneven backlighting;

Use the built-in media player to scroll through all the pictures. the matrix defect will be noticed a lot.!

If there is a broken pixel, you will definitely see it as a black, white or colored point in any area of ​​the screen.

The link can be used to DOWNLOAD THE ARCHIVE (28 test images), unpack on a flash card and insert into the USB port of your TV!

Checking with a Laptop

You can also use a special program to test the TV screen or monitor

This program allows you to evaluate Not only the presence or absence of dead pixels on the display, but also the uniformity of the matrix backlight, geometric distortion and response time of the matrix.

Verification with a professional

You can Call the wizard to set up your TV. As well as checking the screen of your TV or monitor for dead pixels!

When buying a TV or monitor, sellers offer to use an additional service. check for dead pixels. over, the service is paid, costing from 500 rubles and more. If you find a defect at home, you will NOT be able to return the TV back, they explain. After all, this is not a guarantee case, and they are right. In fact, you can perform such a matrix test yourself and for free, there is nothing complicated about it. It is enough just to bring a special one or pictures for verification with you on a USB flash drive, read our article before.

Allowable amount

How many dead pixels are acceptable? The answer to this question is contained in the international quality standard for LCD TVs ISO 13406-2. It identifies 3 types of defective points:

  • Open or white. such pixels freeze in the open state and constantly glow white.
  • Closed or black. such pixels freeze when closed and constantly glow black.
  • Colored. in such pixels the control transistor fails, and they are constantly lit in one of 3 colors: red, green or blue.

Also LCD devices are divided into 4 classes. The first class is the highest, the presence of defective points is generally not allowed in the matrix of devices of this class. The bulk of devices on the market are second class. The standard defines the allowable number of different types of defective dots depending on the maximum resolution it supports. Information for popular 2nd class devices is shown in the table below.

Pixel Type Max Resolution1280 × 720 (720p, HD Ready)1920 × 1080 (1080p, Full HD)
1. White24
2. Black24
3. Coloredfiveten
TOTALnineeighteen

Warranty case

Why are some dead pixels allowed? The fact is that the technology for the production of LCD matrixes is very complex, and not even every device manufacturer can afford their own production. And such a defect can only be detected on the assembled device. If the manufacturer scraps screens even with minor defects, then the price of TVs and monitors will increase several times. Therefore, such a compromise was found:

  • Manufacturers keep production at the same level and do NOT raise prices.
  • Buyers admit the presence of a certain number of dead pixels, which is NOT a warranty case. In this case, the buyer has the right to check the display before purchasing.

How to check

To check the screen for defects, you need to successively submit pictures of the primary colors to it, and at the same time carefully look at it, trying to find points of the second color. This is what broken pixels look like. For example, when there is a white picture on the screen, it is easy to detect black and colored dots. If black is served, then it is easy to detect white dots, etc. Before testing with the TV off, make sure there are no dust particles or other debris on the screen.

Recovery

There are several ways to recover dead pixels found during the test. They give the result extremely rarely and only in the correction of colored dots (3rd type). Tests also show that it usually helps for a short time, the next day the pixel fails again. Plus, you can easily mess up neighboring points. Therefore, we highly do not recommend doing recovery, but we will still consider the methods:

  • Programmatic approach. A matrix picture is displayed on the screen, in which dots of different colors are randomly displayed. The problem pixel should be restored within 20 minutes;
  • Mechanical approach. I turn off the TV, press on the broken pixel with a napkin, turn on the device and stop pressing. This method can harm the matrix.
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What pixel defects are there

Beats call any Abnormal pixels, Visible against the general background, but this is not entirely correct. Really broken or dead pixels are only those in which the transistor has failed. They do NOT glow in any color and just remain black, falling out of the matrix grid. Clearly visible on a white background.

Hanging pixels on the left and right, broken pixels in the center / digital-boom.Ru

There are also frozen or stuck pixels. these are red, green, blue or white dots, which are clearly visible on a black background. They occur when subpixels freeze when updating colors.

How to check the display

You can visually determine the absence of defective pixels by carefully examining a solid white, black, red, green and blue background. To do this, you need to download such pictures to a USB flash drive and play them on the device you like. If none of the dots are out of the general color, then everything is in order with the screen.

Another option is to use special software if you can run it. In fact, these are the same color pictures, but in a more convenient format for applications or online services.

  • Dead Pixel Tester is a simple open source utility for Windows. After starting, you need to select the mode and carefully look at the screen.
  • Injuredpixels is another free Windows app. Colors are switched by mouse or using arrows.
  • Dead Pixel Buddy is an online color checker tool. Works in any browser, including mobile ones. Don’t forget to enable full screen mode.
  • LCD DeadPixel Test is another online service. Choose a color, expand the window to full screen and check.

How to check

To check the screen for defects, you need to successively submit pictures of the primary colors to it, and at the same time carefully look at it, trying to find points of the second color. This is what broken pixels look like. For example, when there is a white picture on the screen, it is easy to detect black and colored dots. If black is served, then it is easy to detect white dots, etc. Before testing with the TV off, make sure there are no dust particles or other debris on the screen.

Allowable amount

How many dead pixels are acceptable? The answer to this question is contained in the international quality standard for LCD TVs ISO 13406-2. It identifies 3 types of defective points:

  • Open or white. such pixels freeze in the open state and constantly glow white.
  • Closed or black. such pixels freeze when closed and constantly glow black.
  • Colored. in such pixels the control transistor fails, and they are constantly lit in one of 3 colors: red, green or blue.

Also LCD devices are divided into 4 classes. The first class is the highest, the presence of defective points is generally not allowed in the matrix of devices of this class. The bulk of devices on the market are second class. The standard defines the allowable number of different types of defective dots depending on the maximum resolution it supports. Information for popular 2nd class devices is shown in the table below.

Pixel Type Max Resolution1280 × 720 (720p, HD Ready)1920 × 1080 (1080p, Full HD)
1. White24
2. Black24
3. Coloredfiveten
TOTALnineeighteen

Checking a new TV for dead pixels from a flash drive

If you buy a modern TV with a USB connector, then it’s very easy to check for dead pixels.

Photo 1

The archive below contains 9 photos with a resolution (1920 × 1080 pix) and movie trailer format 1920 × 1080 mkv HD. They need to be moved to a USB flash drive.

Install the USB stick into the USB connector of the new TV.

Using the TV remote control in the menu. Connect a USB flash drive. Then select view photos pointed in the menu to our test photos.

In turn, you view 9 colors of photos and in the case of a dead pixel or a few dead pixels, we will see them on the TV screen.

Photo 2

Watching each of the 9 screensavers, you can easily determine the presence or absence of dead pixels on the TV screen even before paying for the purchase. Do not forget to check the sound quality in the folder there is a movie trailer in good quality and with good sound.

Photo 3

How to remove dead pixels

Since black pixels are the result of damage to the transistor, they cannot be repaired without replacing THESE components. And this is almost unrealistic even in laboratory conditions. The situation is different with colored dots, which appear due to freezing of subpixels. You can try to remove them.

Black picture to check dead pixels

To save yourself from wasting time and money, I recommend checking the TV before buying with a flash drive.

Files to check the TV for dead pixels

The files are archived by WinRar. Use the link below and download the archiver.

You will need a free app, a Q-tIP, and a little patience.

Warranty case

Why are some dead pixels allowed? The fact is that the technology for the production of LCD matrixes is very complex, and not even every device manufacturer can afford their own production. And such a defect can only be detected on the assembled device. If the manufacturer scraps screens even with minor defects, then the price of TVs and monitors will increase several times. Therefore, such a compromise was found:

  • Manufacturers keep production at the same level and do NOT raise prices.
  • Buyers admit the presence of a certain number of dead pixels, which is NOT a warranty case. In this case, the buyer has the right to check the display before purchasing.