ThinkWiki - User contributions [en]

Problem with Pixel Error

2005-05-28T20:51:37Z

217.231.107.132: /* External sources */

This page provides information about pixel and subpixel errors.

==What are dead pixels or dead subpixels?==
Dead Pixels are a phenomena caused by the technology of LCD displays. TFT displays consist of a huge number of individual display cells, each controlled by its own transistor. I.E. a display with a resolution of 1024x768 pixels consists of 1024x768x3 = 2,36 million cells. A such enormous number makes the production of a display without any faulty cell difficult. The more strict the quality restrictions are, the more expensive the panels get, because this simply means raising the number of garbage panels.

==Types of pixel errors==
Here is a listing of possible types of dead pixels / subpixels:
{| cellspacing=0 cellpadding=2 border=1 style="text-align:center"
! pixel type<hr />state type !! pixel !! red subpixel !! green subpixel !! blue subpixel
|-
| always lit ||   ·   ||   ·   ||   ·   ||   ·  
|-
| always unlit ||   ·   ||   ·     ·   ||   ·     ·   ||   ·     ·  
|}

You can notice here, that always lit complete pixels, red subpixels and green subpixels are the most annoying ones. Also, dead pixels located closer to the center of the screen are more annoying than such located closer to the edge of the screen.

Dead pixels do not always have to be a constant phenomena. You might in fact experience your pixel in question be faulty at times and working perfectly at other times. Or you might experience it to be a little flickering. This is only logical since a faulty transistor might sometimes work and sometimes not, depending on environmental conditions or even just randomly.

{{HINT|The table above also shows you a way of detecting dead pixels and subpixels. Just use plain colored screens.}}

==The ISO 13406-2 norm==
However, to give the concerned customer more transparency when bying LCD displays, the ISO norm 13406-2 was introduced, providing a basis for warranty claims. By assuring one of the classes of this specification, the producer is bound to keep that quality standard throughout the whole production series. However, Manufacturers are not necessarily going with this standard. For values for IBM displays look at [http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-4U9P53 this page].

The values in the following table state the acceptable errors per 1 million pixels. Dead pixels form a cluster when they are within a square of 5x5 pixels.

{| cellspacing=0 cellpadding=2 border=1 style="text-align:center"
! Error class !! Type 1 (always lit pixel) !! Type 2 (always unlit pixel) !! Type 3 (always lit or always unlit subpixel) !! Type 4 (clusters with more than one Type 1 or Type 3 faults) !! Type 4 (clusters of Type 3 faults)
|-
| I || 0 || 0 || 0 || 0 || 0
|-
| II || 2 || 2 || 5 || 0 || 2
|-
| III || 5 || 15 || 50 || 0 || 5
|-
| IV || 50 || 150 || 500 || 5 || 50
|}

==Causes for dead pixels/subpixels==
* As stated above, dead pixels are an inherent feature of the technology/production process of TFT displays. How many of them are in the final displays sold is just a mater of quality control standards.
* Furthermore, they can also accur at random time after production. Transistors can have faults that are not recognizable at production time. These faults may make the transistor stop working after it has been in use for a certain amount of time.
* Mechanical or environmental stress (i.e. heat) can possibly damage a transistor, leading to pixel errors.

==Don't panic!==
Dead pixels are a really common phenomena on TFT displays. In fact there are other things about TFT displays that matter a lot more, like brightness and contrast, picture stability, color reproduction and response time. People just tend to focus on those things that are the most obvious, that's why everyone cries for dead pixels and response time when it comes to TFT displays.

However, as stated above there can be truely annoying types of dead pixels. If their count is higher than the displays quality class permits you might get the device replaced under warranty.
The best thing, however, is to look for dead pixels right after purchase (you might have a chance to return it without special reason then):
* Do it three times over two days - different moods and different environemental light have an influence on your perception.
* Be concious about how hard it was to find the dead pixel - if it was really hard it can't be too bothering.
* Also make sure that what you consider a dead pixel isn't just a piece of dirt or dust.

==Solutions==
Besides some april jokes there isn't really any solution except looking for a replacement.

However, for {{Windows}} an interesting program exists that can help you making annoying subpixels and pixels more bearable. It works by trying to compensate dead a subpixel by adjusting the values for the remaining working subpixels. This way you can i.e. get rid of a most annoying always lit red subpixel. The program is german only and a download link can be found in its german [http://www.prad.de/board/thread.php?threadid=11797 PixChanger discussion].

==External sources==
* [http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-4U9P53 IBMs page on defective pixel display replacement criteria]
* [http://graphics.tomshardware.com/display/20030319/index.html "An autopsy of Dead Pixels" at Tom's Hardware Guide]

Problem with Pixel Error

2005-05-28T20:49:54Z

217.231.107.132:

This page provides information about pixel and subpixel errors.

==What are dead pixels or dead subpixels?==
Dead Pixels are a phenomena caused by the technology of LCD displays. TFT displays consist of a huge number of individual display cells, each controlled by its own transistor. I.E. a display with a resolution of 1024x768 pixels consists of 1024x768x3 = 2,36 million cells. A such enormous number makes the production of a display without any faulty cell difficult. The more strict the quality restrictions are, the more expensive the panels get, because this simply means raising the number of garbage panels.

==Types of pixel errors==
Here is a listing of possible types of dead pixels / subpixels:
{| cellspacing=0 cellpadding=2 border=1 style="text-align:center"
! pixel type<hr />state type !! pixel !! red subpixel !! green subpixel !! blue subpixel
|-
| always lit ||   ·   ||   ·   ||   ·   ||   ·  
|-
| always unlit ||   ·   ||   ·     ·   ||   ·     ·   ||   ·     ·  
|}

You can notice here, that always lit complete pixels, red subpixels and green subpixels are the most annoying ones. Also, dead pixels located closer to the center of the screen are more annoying than such located closer to the edge of the screen.

Dead pixels do not always have to be a constant phenomena. You might in fact experience your pixel in question be faulty at times and working perfectly at other times. Or you might experience it to be a little flickering. This is only logical since a faulty transistor might sometimes work and sometimes not, depending on environmental conditions or even just randomly.

{{HINT|The table above also shows you a way of detecting dead pixels and subpixels. Just use plain colored screens.}}

==The ISO 13406-2 norm==
However, to give the concerned customer more transparency when bying LCD displays, the ISO norm 13406-2 was introduced, providing a basis for warranty claims. By assuring one of the classes of this specification, the producer is bound to keep that quality standard throughout the whole production series. However, Manufacturers are not necessarily going with this standard. For values for IBM displays look at [http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-4U9P53 this page].

The values in the following table state the acceptable errors per 1 million pixels. Dead pixels form a cluster when they are within a square of 5x5 pixels.

{| cellspacing=0 cellpadding=2 border=1 style="text-align:center"
! Error class !! Type 1 (always lit pixel) !! Type 2 (always unlit pixel) !! Type 3 (always lit or always unlit subpixel) !! Type 4 (clusters with more than one Type 1 or Type 3 faults) !! Type 4 (clusters of Type 3 faults)
|-
| I || 0 || 0 || 0 || 0 || 0
|-
| II || 2 || 2 || 5 || 0 || 2
|-
| III || 5 || 15 || 50 || 0 || 5
|-
| IV || 50 || 150 || 500 || 5 || 50
|}

==Causes for dead pixels/subpixels==
* As stated above, dead pixels are an inherent feature of the technology/production process of TFT displays. How many of them are in the final displays sold is just a mater of quality control standards.
* Furthermore, they can also accur at random time after production. Transistors can have faults that are not recognizable at production time. These faults may make the transistor stop working after it has been in use for a certain amount of time.
* Mechanical or environmental stress (i.e. heat) can possibly damage a transistor, leading to pixel errors.

==Don't panic!==
Dead pixels are a really common phenomena on TFT displays. In fact there are other things about TFT displays that matter a lot more, like brightness and contrast, picture stability, color reproduction and response time. People just tend to focus on those things that are the most obvious, that's why everyone cries for dead pixels and response time when it comes to TFT displays.

However, as stated above there can be truely annoying types of dead pixels. If their count is higher than the displays quality class permits you might get the device replaced under warranty.
The best thing, however, is to look for dead pixels right after purchase (you might have a chance to return it without special reason then):
* Do it three times over two days - different moods and different environemental light have an influence on your perception.
* Be concious about how hard it was to find the dead pixel - if it was really hard it can't be too bothering.
* Also make sure that what you consider a dead pixel isn't just a piece of dirt or dust.

==Solutions==
Besides some april jokes there isn't really any solution except looking for a replacement.

However, for {{Windows}} an interesting program exists that can help you making annoying subpixels and pixels more bearable. It works by trying to compensate dead a subpixel by adjusting the values for the remaining working subpixels. This way you can i.e. get rid of a most annoying always lit red subpixel. The program is german only and a download link can be found in its german [http://www.prad.de/board/thread.php?threadid=11797 PixChanger discussion].

==External sources==
* [http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-4U9P53 IBMs page on defective pixel display replacement criterial]
* [http://graphics.tomshardware.com/display/20030319/index.html "An autopsy of Dead Pixels" at Tom's Hardware Guide]

Known Problems

2005-05-28T20:45:30Z

217.231.107.132:

Information on known problems with certain Thinkpad models.

Choose (or create) a problem:

===Display Problems===
*[[Problem with red tinted display | Red tint problem]] (TP 23)

*[[Problem with red display shadow | Red shadow problem]] (TP T41p)

*[[Problem with DVI throughput | Problem with DVI throughput on port replicators and docks]] (models from 2000-2004)

*[[Problem with garbled screen | Garbled screen problem]]

*[[Problem with video related system lockup | Video-related system lockups]] (TP T2x)

*[[Problem with black X | Unmovable square black X in X]] (TP T2x)

*[[Problem with Pixel Error | Dead pixels on TFT displays ]] (all models)

===Network Problems===
*[[Problem with 3Com 10/100 Ethernet card not being recognized]] (models with that card)

===Power Management and Battery Problems===
*[[Problem with Thinkpad 600 batteries | Battery problem]] (TP 600/E/X)

*[[Problem with fan noise | Fan noise problem]] (TP T4x/p, TP R5x/p)

*[[Problem with high power drain in ACPI sleep | High power drain in ACPI sleep]] (various models)

*[[Problem with LCD backlight remaining on during ACPI sleep | LCD backlight remaining on during ACPI sleep]] (various models)

*[[Problem with display remaining black after resume|Blank display after resume]] (various models)

===Sound Problems===
*[[Problem with broken sound on ThinkPad 600 | Broken sound on ThinkPad 600/E]] (TP 600/E/X, 770Z)

===Misc Problems===
*[[Problem with lm-sensors | Problem with lm_sensors]] (TP 570E, 770X/Z, 600E/X, 240, X20)
*[[Problem with high pitch noises | High pitch noises]] (several models)
*[[Problem with hard drive clicking | Clicking Hard Drive]] (T4x models and other models which ship with Hitachi's 5k80 hard drive)
*[[Problem with Dock USB Ports | Dock USB Ports]] (T30)
*[[Problem with USB 2.0 | USB 2.0 problems]] (T4x)

[[de:Bekannte_Probleme]]

Problem with Pixel Error

2005-05-28T20:41:55Z

217.231.107.132: /* Solutions */

This page provides information about pixel and subpixel errors.

==What are dead pixels or dead subpixels?==
Dead Pixels are a phenomena caused by the technology of LCD displays. TFT displays consist of a huge number of individual display cells, each controlled by its own transistor. I.E. a display with a resolution of 1024x768 pixels consists of 1024x768x3 = 2,36 million cells. A such enormous number makes the production of a display without any faulty cell difficult. The more strict the quality restrictions are, the more expensive the panels get, because this simply means raising the number of garbage panels.

==Types of pixel errors==
Here is a listing of possible types of dead pixels / subpixels:
{| cellspacing=0 cellpadding=2 border=1 style="text-align:center"
! pixel type<hr />state type !! pixel !! red subpixel !! green subpixel !! blue subpixel
|-
| always lit ||   ·   ||   ·   ||   ·   ||   ·  
|-
| always unlit ||   ·   ||   ·     ·   ||   ·     ·   ||   ·     ·  
|}

You can notice here, that always lit complete pixels, red subpixels and green subpixels are the most annoying ones. Also, dead pixels located closer to the center of the screen are more annoying than such located closer to the edge of the screen.

Dead pixels do not always have to be a constant phenomena. You might in fact experience your pixel in question be faulty at times and working perfectly at other times. Or you might experience it to be a little flickering. This is only logical since a faulty transistor might sometimes work and sometimes not, depending on environmental conditions or even just randomly.

{{HINT|The table above also shows you a way of detecting dead pixels and subpixels. Just use plain colored screens.}}

==The ISO 13406-2 norm==
However, to give the concerned customer more transparency when bying LCD displays, the ISO norm 13406-2 was introduced, providing a basis for warranty claims. By assuring one of the classes of this specification, the producer is bound to keep that quality standard throughout the whole production series.

The values in the following table state the acceptable errors per 1 million pixels. Dead pixels form a cluster when they are within a square of 5x5 pixels.

{| cellspacing=0 cellpadding=2 border=1 style="text-align:center"
! Error class !! Type 1 (always lit pixel) !! Type 2 (always unlit pixel) !! Type 3 (always lit or always unlit subpixel) !! Type 4 (clusters with more than one Type 1 or Type 3 faults) !! Type 4 (clusters of Type 3 faults)
|-
| I || 0 || 0 || 0 || 0 || 0
|-
| II || 2 || 2 || 5 || 0 || 2
|-
| III || 5 || 15 || 50 || 0 || 5
|-
| IV || 50 || 150 || 500 || 5 || 50
|}

==Causes for dead pixels/subpixels==
* As stated above, dead pixels are an inherent feature of the technology/production process of TFT displays. How many of them are in the final displays sold is just a mater of quality control standards.
* Furthermore, they can also accur at random time after production. Transistors can have faults that are not recognizable at production time. These faults may make the transistor stop working after it has been in use for a certain amount of time.
* Mechanical or environmental stress (i.e. heat) can possibly damage a transistor, leading to pixel errors.

==Don't panic!==
Dead pixels are a really common phenomena on TFT displays. In fact there are other things about TFT displays that matter a lot more, like brightness and contrast, picture stability, color reproduction and response time. People just tend to focus on those things that are the most obvious, that's why everyone cries for dead pixels and response time when it comes to TFT displays.

However, as stated above there can be truely annoying types of dead pixels. If their count is higher than the displays quality class permits you might get the device replaced under warranty.
The best thing, however, is to look for dead pixels right after purchase (you might have a chance to return it without special reason then):
* Do it three times over two days - different moods and different environemental light have an influence on your perception.
* Be concious about how hard it was to find the dead pixel - if it was really hard it can't be too bothering.
* Also make sure that what you consider a dead pixel isn't just a piece of dirt or dust.

==Solutions==
Besides some april jokes there isn't really any solution except looking for a replacement.

However, for {{Windows}} an interesting program exists that can help you making annoying subpixels and pixels more bearable. It works by trying to compensate dead a subpixel by adjusting the values for the remaining working subpixels. This way you can i.e. get rid of a most annoying always lit red subpixel. The program is german only and a download link can be found in its german [http://www.prad.de/board/thread.php?threadid=11797 PixChanger discussion].

==External sources==
* [http://graphics.tomshardware.com/display/20030319/index.html "An autopsy of Dead Pixels" at Tom's Hardware Guide]

Known Problems

2005-05-28T20:37:25Z

217.231.107.132:

Information on known problems with certain Thinkpad models.

Choose (or create) a problem:

===Display Problems===
*[[Problem with red tinted display | Red tint problem]] (TP 23)

*[[Problem with red display shadow | Red shadow problem]] (TP T41p)

*[[Problem with DVI throughput | Problem with DVI throughput on port replicators and docks]] (models from 2000-2004)

*[[Problem with garbled screen | Garbled screen problem]]

*[[Problem with video related system lockup | Video-related system lockups]] (TP T2x)

*[[Problem with black X | Unmovable square black X in X]] (TP T2x)

*[[Problem with Pixel Error | Dead pixels on TFT display ]] (TP T3x)

===Network Problems===
*[[Problem with 3Com 10/100 Ethernet card not being recognized]] (models with that card)

===Power Management and Battery Problems===
*[[Problem with Thinkpad 600 batteries | Battery problem]] (TP 600/E/X)

*[[Problem with fan noise | Fan noise problem]] (TP T4x/p, TP R5x/p)

*[[Problem with high power drain in ACPI sleep | High power drain in ACPI sleep]] (various models)

*[[Problem with LCD backlight remaining on during ACPI sleep | LCD backlight remaining on during ACPI sleep]] (various models)

*[[Problem with display remaining black after resume|Blank display after resume]] (various models)

===Sound Problems===
*[[Problem with broken sound on ThinkPad 600 | Broken sound on ThinkPad 600/E]] (TP 600/E/X, 770Z)

===Misc Problems===
*[[Problem with lm-sensors | Problem with lm_sensors]] (TP 570E, 770X/Z, 600E/X, 240, X20)
*[[Problem with high pitch noises | High pitch noises]] (several models)
*[[Problem with hard drive clicking | Clicking Hard Drive]] (T4x models and other models which ship with Hitachi's 5k80 hard drive)
*[[Problem with Dock USB Ports | Dock USB Ports]] (T30)
*[[Problem with USB 2.0 | USB 2.0 problems]] (T4x)

[[de:Bekannte_Probleme]]

Talk:Problem with Pixel Error

2005-05-28T20:34:16Z

217.231.107.132:

During the first day of work, it didn't strike me (even though I tried hard to check for pixel errors, but maybe I didn't have the right lighting) - but today on my 2nd day of use, I detected a blue pixel.

Questions
* Is this a reason to return the device or does it happen anyway sooner or later?
* Can there anything be done about it?
* What might have caused the pixel error? I believe there is a irregular spot surrounding the very pixel (like a puddle of water 1 cm in diameter) - but I certainly didn't put anything between screen and keyboard when closing.
----
Hei,

hope the article answers most of your questions. I don't have any IBM specific information though. Concerning your "watery spot"...it might be the outcome of not putting anything between keyboard and display. ;-) It's a common phenomena that the keyboard leaves markings on the display. Mostly it is just human skin oil that remains on the keys and then on the display. This can be avoided by putting a very thin layer of paper or textile between them. However, if during a transport the pressure on the back of the display is too strong, the keys or trackpoint keys might leave more severe markings. There is a chance that they might also have caused the dead pixel under such circumstance. Wyrfel
----

Talk:Problem with Pixel Error

2005-05-28T20:34:03Z

217.231.107.132:

Template:Windows

2005-05-28T20:27:49Z

217.231.107.132:

[[:Category:Windows|Windows]][[Category:Windows]]

Problem with Pixel Error

2005-05-28T20:26:06Z

217.231.107.132:

This page provides information about pixel and subpixel errors.

==What are dead pixels or dead subpixels?==
Dead Pixels are a phenomena caused by the technology of LCD displays. TFT displays consist of a huge number of individual display cells, each controlled by its own transistor. I.E. a display with a resolution of 1024x768 pixels consists of 1024x768x3 = 2,36 million cells. A such enormous number makes the production of a display without any faulty cell difficult. The more strict the quality restrictions are, the more expensive the panels get, because this simply means raising the number of garbage panels.

==Types of pixel errors==
Here is a listing of possible types of dead pixels / subpixels:
{| cellspacing=0 cellpadding=2 border=1 style="text-align:center"
! pixel type<hr />state type !! pixel !! red subpixel !! green subpixel !! blue subpixel
|-
| always lit ||   ·   ||   ·   ||   ·   ||   ·  
|-
| always unlit ||   ·   ||   ·     ·   ||   ·     ·   ||   ·     ·  
|}

You can notice here, that always lit complete pixels, red subpixels and green subpixels are the most annoying ones. Also, dead pixels located closer to the center of the screen are more annoying than such located closer to the edge of the screen.

Dead pixels do not always have to be a constant phenomena. You might in fact experience your pixel in question be faulty at times and working perfectly at other times. Or you might experience it to be a little flickering. This is only logical since a faulty transistor might sometimes work and sometimes not, depending on environmental conditions or even just randomly.

{{HINT|The table above also shows you a way of detecting dead pixels and subpixels. Just use plain colored screens.}}

==The ISO 13406-2 norm==
However, to give the concerned customer more transparency when bying LCD displays, the ISO norm 13406-2 was introduced, providing a basis for warranty claims. By assuring one of the classes of this specification, the producer is bound to keep that quality standard throughout the whole production series.

The values in the following table state the acceptable errors per 1 million pixels. Dead pixels form a cluster when they are within a square of 5x5 pixels.

{| cellspacing=0 cellpadding=2 border=1 style="text-align:center"
! Error class !! Type 1 (always lit pixel) !! Type 2 (always unlit pixel) !! Type 3 (always lit or always unlit subpixel) !! Type 4 (clusters with more than one Type 1 or Type 3 faults) !! Type 4 (clusters of Type 3 faults)
|-
| I || 0 || 0 || 0 || 0 || 0
|-
| II || 2 || 2 || 5 || 0 || 2
|-
| III || 5 || 15 || 50 || 0 || 5
|-
| IV || 50 || 150 || 500 || 5 || 50
|}

==Causes for dead pixels/subpixels==
* As stated above, dead pixels are an inherent feature of the technology/production process of TFT displays. How many of them are in the final displays sold is just a mater of quality control standards.
* Furthermore, they can also accur at random time after production. Transistors can have faults that are not recognizable at production time. These faults may make the transistor stop working after it has been in use for a certain amount of time.
* Mechanical or environmental stress (i.e. heat) can possibly damage a transistor, leading to pixel errors.

==Don't panic!==
Dead pixels are a really common phenomena on TFT displays. In fact there are other things about TFT displays that matter a lot more, like brightness and contrast, picture stability, color reproduction and response time. People just tend to focus on those things that are the most obvious, that's why everyone cries for dead pixels and response time when it comes to TFT displays.

However, as stated above there can be truely annoying types of dead pixels. If their count is higher than the displays quality class permits you might get the device replaced under warranty.
The best thing, however, is to look for dead pixels right after purchase (you might have a chance to return it without special reason then):
* Do it three times over two days - different moods and different environemental light have an influence on your perception.
* Be concious about how hard it was to find the dead pixel - if it was really hard it can't be too bothering.
* Also make sure that what you consider a dead pixel isn't just a piece of dirt or dust.

==Solutions==
Besides some april jokes there isn't really any solution except looking for a replacement.

However, for {{Windows}} an interesting program exists that can help you making annoying subpixels and pixels more bearable. It works by trying to compensate dead subpixel by adjusting the values for the remaining working subpixels. This way you can i.e. get rid of a most annoying always lit red subpixel. The program is german only and a download link can be found in its german [http://www.prad.de/board/thread.php?threadid=11797 PixChanger discussion].

==External sources==
* [http://graphics.tomshardware.com/display/20030319/index.html "An autopsy of Dead Pixels" at Tom's Hardware Guide]