lcd panel edid eeprom error brands

I"m faced with an interesting issue! One of our client Dell laptop does not show POST/Dell splash screen when powered on. Eventually, after a minute or two, the Windows login screen appears. I"ve replaced the LCD panel, updated BIOS, drained power, reseated everything possible, and even re-imaged the HD. Dell diagnostics gives me this error: LCD EDID - Unable to access EDI EEPROM, even after replacing the LCD panel. I"m beginning to suspect that the motherboard is the culprit here. Anyone seen this type of issue before?Just out of curiosity, what does Dell Support have to say about that error?

I"m faced with an interesting issue! One of our client Dell laptop does not show POST/Dell splash screen when powered on. Eventually, after a minute or two, the Windows login screen appears. I"ve replaced the LCD panel, updated BIOS, drained power, reseated everything possible, and even re-imaged the HD. Dell diagnostics gives me this error: LCD EDID - Unable to access EDI EEPROM, even after replacing the LCD panel. I"m beginning to suspect that the motherboard is the culprit here. Anyone seen this type of issue before?Just out of curiosity, what does Dell Support have to say about that error?

SOLVED! I replaced the LVDS cable, and I am now able to see the Dell splash screen and also access BIOS and PXE boot. Diagnostics no longer reports an error. It"s a beautiful day - birds are chirping, flowers are blooming, people are happy. Thank you all for the support!!!

The 24C04 is a 4K Bit EEPROM used to store monitor display control data. This memory is not directly accessible by the consumer; the adjustments are entered into the OSD menu, then the MCU writes the new data to the EEPROM. The information stored in the EEPROM is limited to specific parameters controlled by the monitor MCU.

The 24C02 is a 2K Bit EEPROM used to store monitor EDID information for use by the host PC. This information is written at the factory, and cannot be altered or deleted by the consumer.

EDID data exchange is a standardized means for a display to communicate its capabilities to a source device. The premise of this communications is for the display to relay its operational characteristics, such as its native resolution, to the attached source, and then allow the source to generate the necessary video characteristics to match the needs of the display. This maximizes the functional compatibility between devices without requiring a user to configure them manually, thus reducing the potential for incorrect settings and adjustments that could compromise the quality of the displayed images and overall reliability of the system.

Generally, the source device will be a computer graphics card on a desktop or laptop PC, but provisions are in place for many other devices, including HDTV receivers and DVRs, DVD and Blu-ray Disc players, and even gaming consoles, to read EDID and output video accordingly. Originally developed for use between analog computer-video devices with VGA ports, EDID is also now implemented for DVI, HDMI, and DisplayPort.

EDID was developed by VESA - the Video Electronics Standards Association, with version 1.0 introduced in 1994 within version 1.0 of the DDC standard. See Table 1.

Prior to the development of EDID, pins 4, 11, 12, and 15 on the VGA connector were sometimes used to define monitor capabilities. These ID bit pins carried either high or low values to define different screen resolutions. VESA extended this scheme by redefining VGA connector pins 9, 12, and 15 as a serial bus in the form of the DDC - Display Data Channel. This allowed for much more information to be exchanged, so that EDID and other forms of communication were possible between the source and the display.

As display types and capabilities increased, 128 bytes became insufficient, and both EDID and DDC were extended so that multiple 128-byte data blocks could be exchanged. This is known as E-EDID and has been implemented in many consumer devices. In fact, the CEA - Consumer Electronics Association has defined its own EDID extensions to cover additional video formats and to support advanced multi-channel audio capabilities.

In December 2007, VESA released DisplayID, a second generation of EDID. It is intended to replace all previous versions. DisplayID is a variable length data structure, of up to 256 bytes, that conveys display-related information to attached source devices. It is meant to encompass PC display devices, consumer televisions, and embedded displays such as LCD screens within laptops, without the need for multiple extension blocks. DisplayID is not directly backward compatible with previous EDID/E-EDID versions, but is not yet widely incorporated in AV products.

The base EDID information of a display is conveyed within a 128-byte data structure that contains pertinent manufacturer and operation-related data. See Table 2. The current EDID version defines the structure as follows:

The general structure of CEA-861 extension data is shown in Table 3. CEA-861 allows for a variable number of 18-byte detailed timing descriptions to be included. For example, video timing details for 1080i, which is popular for consumer displays but not for PCs, can be communicated. CEA-861 also specifies a variable length "CEA Data Block Collection" for describing parameters such as display colorimetry, and advanced audio capabilities including surround sound format, audio sampling rate, and even speaker configuration and placement. The significance of the CEA-861 extension is that it aims to address previous operational disparities experienced with integrating consumer-based display devices into computer-based commercial AV systems, allowing for proper conveyance of EDID information between devices.

EDID information is typically exchanged when the video source starts up. The DDC specifications define a +5V supply connection for the source to provide power to a display"s EDID circuitry so that communication can be enabled, even if the display is powered off. At startup, the video source will send a request for EDID over the DDC. The EDID/DDC specifications support hot plug detection, so that EDID information can also be exchanged whenever a display is reconnected to a video source. Hot plug detection is not supported for VGA, but is supported in digital interfaces including DVI, HDMI, and DisplayPort. For these interfaces, the display device will supply a voltage on an HPD - Hot Plug Detect pin, to signal to the video source device that it is connected. The absence of a voltage on the HPD pin indicates disconnection. The video source device monitors the voltage on the HPD pin and initiates EDID requests as it senses incoming voltage.

Display devices can have various levels of EDID implementation and, in some cases, they may lack EDID information altogether. Such inconsistencies can cause operational issues ranging from overscan and resolution problems, to the display device not displaying the source content at all.

Possible CauseThe source device, such as a PC graphics card, or laptop, cannot read the EDID information from the display. As a result, in some cases the PC will not output any video signal.

While hot plug detection is supported for DVI, HDMI, and DisplayPort, EDID communication problems can arise from inconsistencies in the implementation of HPD signaling between devices from different manufacturers. This frequently becomes an issue for professional integration, since the ability to switch digital video signals is a necessity.

Possible CauseA PC cannot read the EDID information, so it defaults to a standard resolution, such as 640x480. If the user subsequently attempts to manually set the resolution to match the display, some graphics card drivers may enforce the lower default resolution and create a scrolling/panning desktop without actually changing the video resolution.

The PC is able to read the EDID information, but the graphics card limits the output resolution to XGA 1024x768, a resolution most displays can accommodate, ensuring a usable image and reducing the likelihood of no image being displayed. If this does not match the native resolution of the display, fonts will likely appear to be abnormally large, small, or fuzzy.

The PC is connected to multiple displays with different native resolutions. Since it can only read EDID from one display, the output will be mismatched in resolution with all other displays, resulting in less than optimal image quality, or no image displayed at all. This issue is a common occurrence in professional systems when video signals need to be distributed or routed to multiple displays.

Software such as Extron EDID Manager can be used to help troubleshoot possible compatibility issues between the display device and the source. EDID Manager is available as a free download from Extron"s Web site, www.extron.com. It is a useful software tool that allows you to read the display"s EDID and determine whether a graphic card and the display device may be experiencing EDID handshake problems.

AV systems typically comprise several remotely located displays and often include multiple source devices. It is important to realize this can potentially contribute to EDID-related issues. The necessity to switch, distribute, and route signals from sources to displays presents a considerable challenge in terms of ensuring proper EDID communications and therefore reliable system operation.

For example, systems that employ RGBHV-based distribution have no means of passing EDID information from the display to the source. This could become problematic in system designs where laptops and computers with expectation of seeing EDID are connected into the system. Since EDID information is not being provided to these devices, some of the aforementioned EDID communication issues may occur.

Extron products include features to help prevent or solve many of them by properly managing EDID communications between sources and displays in AV systems. These features provide automatic and continuous EDID management with attached source devices, ensuring proper power-up and reliable output of content.

EDID Emulation is a feature of many Extron DVI and HDMI products, including switchers, distribution amplifiers, and matrix switchers. It maintains constant EDID communication with source devices by providing pre-stored EDID information for various signal resolutions. A user can select the desired signal resolution, and then the corresponding EDID block is conveyed to all attached source devices. This EDID information is constantly available to the sources, even in a switching application where inputs are regularly selected and de-selected. The output of the sources should match the native resolution of the intended display device.

EDID Minder® is an advanced, Extron exclusive technology for EDID management. It encompasses EDID Emulation, but also incorporates an additional level of "intelligence." Extron products with EDID Minder® can communicate with the display device, and automatically capture and store EDID information from the display. See Figure 3. This captured information can then be used as the reference EDID for the sources. EDID Minder® is a standard feature in most Extron DVI and HDMI extenders, switchers, distribution amplifiers, and matrix switchers, as well as products that incorporate DVI or HDMI switching.

The functional role of a given product as a distribution amplifier, switcher, or matrix switcher determines the complexity of EDID Minder® implementation. Matrix switching environments represent the most difficult EDID management situation, with simultaneous EDID communications required for multiple inputs and outputs. The displays connected to the outputs are very likely to be of different models and native resolutions. The EDID information between them is different and needs to be conveyed to the source devices. Proper EDID management within the system is crucial to consistent and reliable operation.

Extron HDMI and DVI matrix switchers with EDID Minder® achieve this by managing EDID communications for each input/output tie. EDID Minder® first analyzes the EDID for all displays connected to the system, applies a complex algorithm to determine a common resolution, refresh rate and color space, and then uses the EDID protocol to set up the input sources. This powerful convenience feature simplifies system setup for the integrator, helps ensure consistent and reliable image display, and makes system operation virtually transparent to the end user.

I get the above error message and bluescreen when the computer is just sitting idle does nothing.  Usually, it"s when the internet is open, but not surf.  Can someone help me understand this.  The graphics card is an Intel 82945 G express shipset family and I checked to see if it is up-to-date and the pilot said he is up to date.

Service driver or defective peripheral system. A chauffeur service or defective peripheral system could be responsible for this error. The hardware problems, such as BIOS incompatibilities, conflicts of memory and IRQ conflicts can also generate this error.

If the verification of the message bug list a driver by name, disable or remove that driver. In addition, disable or remove drivers or services that have been recently added. If the error occurs during the startup sequence and the system partition is formatted with the NTFS file system, you may be able to use Safe Mode to rename or to delete the faulty driver. If the driver is used as part of the start-up procedure of the system Safe Mode, you must start the computer by using the Recovery Console to access the file.

If the problem is associated with Win32k.sys, the source of the error may be a third-party remote control program. If this software is installed, you can remove the system startup service using the recovery and then Console by removing the offending system service file.

Check the system log in Event Viewer for additional error messages that might help identify the device or driver responsible for control of bug 0x1E. You can disable the cache in memory of the BIOS to try to resolve the error. You must also run the diagnostics of material, especially the scanner memory, which provides the manufacturer of the system. For more information about these procedures, see the manual of your computer.

The error that generates this message may occur after the first reboot during Windows Setup, or after installation is complete. A possible cause of the error is lack of disk space for installation and the system BIOS incompatibilities. For any problems during the installation of Windows that are associated with lack of disk space, reduce the number of files on the hard disk drive target. Search and delete temporary files that you do not have to have, files hidden Internet, application backup files and files saved.chk, which contain fragments of files on disk scans. You can also use an another hard disk drive with more free space for the installation.

Extended Display Identification Data (EDID) and Enhanced EDID (E-EDID) are metadata formats for display devices to describe their capabilities to a video source (e.g. graphics card or set-top box). The data format is defined by a standard published by the Video Electronics Standards Association (VESA).

The EDID data structure includes manufacturer name and serial number, product type, phosphor or filter type (as chromaticity data), timings supported by the display, display size, luminance data and (for digital displays only) pixel mapping data.

DisplayID is a VESA standard targeted to replace EDID and E-EDID extensions with a uniform format suited for both PC monitor and consumer electronics devices.

EDID structure (base block) versions range from v1.0 to v1.4; all these define upwards-compatible 128-byte structures. Version 2.0 defined a new 256-byte structure but it has been deprecated and replaced by E-EDID which supports multiple extension blocks.HDMI versions 1.0–1.3c use E-EDID v1.3.

Before Display Data Channel (DDC) and EDID were defined, there was no standard way for a graphics card to know what kind of display device it was connected to. Some VGA connectors in personal computers provided a basic form of identification by connecting one, two or three pins to ground, but this coding was not standardized.

This problem is solved by EDID and DDC, as it enables the display to send information to the graphics card it is connected to. The transmission of EDID information usually uses the Display Data Channel protocol, specifically DDC2B, which is based on I²C-bus (DDC1 used a different serial format which never gained popularity). The data is transmitted via the cable connecting the display and the graphics card; VGA, DVI and HDMI are supported.

The EDID is often stored in the monitor in the firmware chip called serial EEPROM (electrically erasable programmable read-only memory) and is accessible via the I²C-bus at address 0x50. The EDID PROM can often be read by the host PC even if the display itself is turned off.

Many software packages can read and display the EDID information, such as read-edidMicrosoft Windows and the X.Org Server for Linux and BSD unix. Mac OS X natively reads EDID information and programs such as SwitchResX

E-EDID was introduced at the same time as E-DDC, which supports multiple extensions blocks and deprecated EDID version 2.0 structure (it can be incorporated in E-EDID as an optional extension block). Data fields for preferred timing, range limits, and monitor name are required in E-EDID. E-EDID also supports dual GTF timings and aspect ratio change.

Some graphics card drivers have historically coped poorly with the EDID, using only its standard timing descriptors rather than its Detailed Timing Descriptors (DTDs). Even in cases where the DTDs were read, the drivers are/were still often limited by the standard timing descriptor limitation that the horizontal/vertical resolutions must be evenly divisible by 8. This means that many graphics cards cannot express the native resolutions of the most common wide screen flat panel displays and liquid crystal display televisions. The number of vertical pixels is calculated from the horizontal resolution and the selected aspect ratio. To be fully expressible, the size of wide screen display must thus be a multiple of 16×9 pixels. For 1366×768 pixel Wide XGA panels the nearest resolution expressible in the EDID standard timing descriptor syntax is 1360×765 pixels, typically leading to 3 pixel thin black bars. Specifying 1368 pixels as the screen width would yield an unnatural screen height of 769.5 pixels.

Many Wide XGA panels do not advertise their native resolution in the standard timing descriptors, instead offering only a resolution of 1280×768. Some panels advertise a resolution only slightly smaller than the native, such as 1360×765. For these panels to be able to show a pixel perfect image, the EDID data must be ignored by the display driver or the driver must correctly interpret the DTD and be able to resolve resolutions whose size is not divisible by 8. Special programs are available to override the standard timing descriptors from EDID data. Even this is not always possible, as some vendors" graphics drivers (notably those of Intel) require specific registry hacks to implement custom resolutions, which can make it very difficult to use the screen"s native resolution.

Preferred timing mode specified in descriptor block 1. For EDID 1.3+ the preferred timing mode is always in the first Detailed Timing Descriptor. In that case, this bit specifies whether the preferred timing mode includes native pixel format and refresh rate.

The CEA EDID Timing Extension was first introduced in EIA/CEA-861, and has since been updated several times, most notably with the 861-B revision (which was version 3 of the extension, adding Short Video Descriptors and advanced audio capability/configuration information), 861-D (published in July 2006 and containing updates to the audio segments), 861-E in 2008, and 861-F which was published on June 4, 2013.

Version 1 of the extension block (as defined in CEA−861) allowed the specification of video timings only through the use of 18-byte Detailed Timing Descriptors (DTD) (as detailed in EDID 1.3 data format above). In all cases, the "preferred" timing should be the first DTD listed in a CEA EDID Timing Extension.

A method of changing EDID of a memory of a motherboard in response to replacing an LCD panel of a computer with a different one comprises detecting a chipset; reading a SM bus base or GPIO base; activating a writing mechanism; selecting compatible EDID; writing the EDID into the memory; detecting an error; and closing the writing mechanism. The invention can be embodied by means of software rather than hardware. Thus, it is much convenient.

The present invention relates to method of changing settings of a motherboard and more particularly to a method of changing an EDID (extended display identification data) stored in memory of a motherboard by means of software rather than hardware in response to replacing an LCD (liquid crystal display) panel of a computer with a different one.

Conventionally, an LCD panel of computer has a unique EDID which is defined by VESA (Video Electronic Standards Association) standard. Electrical characteristics of an LCD panel are stored in EDID. EDID is a protocol of DDC (display data channel) for enabling a computer to correctly identify specifications of the LCD panel for control. EDID is typically stored in an EEPROM (electrically erasable programmable read-only memory) of a motherboard. This means that EDID is unique to each motherboard. Thus, the motherboard and thus the computer may not function normally if the original LCD panel is replaced by a new one of different brand. For solving this problem, the only method is to remove the EEPROM from the motherboard prior to burning in a compatible EDID into the EEPROM. Further, it is required to remove the EEPROM from the motherboard prior to burning in changed parameters of EDID into the EEPROM if parameters of LCD panel are required to change. In view of the above, it is not convenient. Hence, a need for improvement exists. SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method of changing EDID of a memory of a motherboard in response to replacing an LCD panel of a computer with a different one, comprising the steps of detecting a chipset; reading a SM bus base or GPIO (General Purpose Input Output) base; activating a writing mechanism; selecting compatible EDID; writing the EDID into the memory; detecting error; and closing the writing mechanism.

Referring to FIG. 1, a LCD VGA (Video Graphics Array) controller of the invention accesses EDID of a desired LCD via a SM (system management) bus (or I2C bus) of DVOI (Digital Video Output Interface) and a selector. As such, initialization data for illuminating LCD panel can be obtained. Hence, different LCD panels can be controlled by changing EDID with respect to factors such as brightness adjustment, etc.

Referring to FIG. 2, there is shown a process of the invention. The process comprises the steps of detecting a chipset for determining whether it is VIA 686B or Intel 815 (step 21); reading SM bus base or GPIO (General Purpose Input Output) base (step 22) if the determination step is positive else ending the process; activating a writing mechanism if the reading is correct (step 23); selecting compatible EDID (step 24); writing EDID into EEPROM (step 25); detecting error (step 26) if the writing is correct; and closing the writing mechanism (step 27) prior to ending the process.

Referring to FIG. 3, there is shown a screen of the invention. As shown, a predetermined number of ID files are available to select on the screen. The ID files comprise standard 640*480 pixels (31), standard 800*600 pixels (32), standard 1024*768 single and dual pixels (33 and 34), and others for selecting a bin file (35). The process of the invention will store EDID in memory (e.g., EEPROM) if the selected EDID is compatible with that of the LCD panel. Referring to FIG. 4, stored filenames and associated information are shown on the screen. EDID comprises a number of parameters adapted to change. For example, a maximum horizontal image size is defined in address 15 h, and Gamma value to be transmitted is defined in address 17 h. These parameters are recorded in a bin file. Changes of the parameters can be carried out by editing the bin file and clicking the others (35) option of the above screen to write the changed EDID.

In brief, the invention can carry out a method of changing an EDID stored in memory of a motherboard by means of software rather than hardware if the original LCD panel is replaced by a new one of different brand. As an end, a plug and display feature can be obtained.

1. A method of changing EDID of a memory of a motherboard in response to replacing an LCD panel of a computer with a different one, comprising the steps of:

I rebooted the system and all seemed ok. I pass the POST as usual, however I cannot see the GUI nor CLI when connected with DVI-I. I believe the EDID code for DVI-I has been corrupted.

Reading EDID data from DVI monitor EEPROM is a common use case for the Aardvark I2C/SPI Host Adapter and DVI DDC Breakout Cable. Although the following describes DVI monitor, similar steps can be used for other DVI devices. The goal of this article is to demonstrate how to read several bytes from DVI monitor EEPROM.

The DVI Monitor EEPROM I2C target address is 0x50. The DVI Monitor EEPROM EDID length is 128 byte. In this article, Aardvark adapter reads from DVI Monitor EEPROM EDID data: 128 bytes from memory address 00 I2C target address 0x50. For additional information take a look at the EDID Documentation.

EDID data exchange is a standardized means for a display to communicate its capabilities to a source device. The premise of this communications is for the display to relay its operational characteristics, such as its native resolution, to the attached source, and then allow the source to generate the necessary video characteristics to match the needs of the display. This maximizes the functional compatibility between devices without requiring a user to configure them manually, thus reducing the potential for incorrect settings and adjustments that could compromise the quality of the displayed images and overall reliability of the system.

Generally, the source device will be a computer graphics card on a desktop or laptop PC, but provisions are in place for many other devices, including HDTV receivers and DVRs, DVD and Blu-ray Disc players, and even gaming consoles, to read EDID and output video accordingly. Originally developed for use between analog computer-video devices with VGA ports, EDID is also now implemented for DVI, HDMI, and DisplayPort.

EDID was developed by VESA - the Video Electronics Standards Association, with version 1.0 introduced in 1994 within version 1.0 of the DDC standard. See Table 1.

Prior to the development of EDID, pins 4, 11, 12, and 15 on the VGA connector were sometimes used to define monitor capabilities. These ID bit pins carried either high or low values to define different screen resolutions. VESA extended this scheme by redefining VGA connector pins 9, 12, and 15 as a serial bus in the form of the DDC - Display Data Channel. This allowed for much more information to be exchanged, so that EDID and other forms of communication were possible between the source and the display.

As display types and capabilities increased, 128 bytes became insufficient, and both EDID and DDC were extended so that multiple 128-byte data blocks could be exchanged. This is known as E-EDID and has been implemented in many consumer devices. In fact, the CEA - Consumer Electronics Association has defined its own EDID extensions to cover additional video formats and to support advanced multi-channel audio capabilities.

In December 2007, VESA released DisplayID, a second generation of EDID. It is intended to replace all previous versions. DisplayID is a variable length data structure, of up to 256 bytes, that conveys display-related information to attached source devices. It is meant to encompass PC display devices, consumer televisions, and embedded displays such as LCD screens within laptops, without the need for multiple extension blocks. DisplayID is not directly backward compatible with previous EDID/E-EDID versions, but is not yet widely incorporated in AV products.

The base EDID information of a display is conveyed within a 128-byte data structure that contains pertinent manufacturer and operation-related data. See Table 2. The current EDID version defines the structure as follows:

The general structure of CEA-861 extension data is shown in Table 3. CEA-861 allows for a variable number of 18-byte detailed timing descriptions to be included. For example, video timing details for 1080i, which is popular for consumer displays but not for PCs, can be communicated. CEA-861 also specifies a variable length "CEA Data Block Collection" for describing parameters such as display colorimetry, and advanced audio capabilities including surround sound format, audio sampling rate, and even speaker configuration and placement. The significance of the CEA-861 extension is that it aims to address previous operational disparities experienced with integrating consumer-based display devices into computer-based commercial AV systems, allowing for proper conveyance of EDID information between devices.

EDID information is typically exchanged when the video source starts up. The DDC specifications define a +5V supply connection for the source to provide power to a display"s EDID circuitry so that communication can be enabled, even if the display is powered off. At startup, the video source will send a request for EDID over the DDC. The EDID/DDC specifications support hot plug detection, so that EDID information can also be exchanged whenever a display is reconnected to a video source. Hot plug detection is not supported for VGA, but is supported in digital interfaces including DVI, HDMI, and DisplayPort. For these interfaces, the display device will supply a voltage on an HPD - Hot Plug Detect pin, to signal to the video source device that it is connected. The absence of a voltage on the HPD pin indicates disconnection. The video source device monitors the voltage on the HPD pin and initiates EDID requests as it senses incoming voltage.

Display devices can have various levels of EDID implementation and, in some cases, they may lack EDID information altogether. Such inconsistencies can cause operational issues ranging from overscan and resolution problems, to the display device not displaying the source content at all.

Possible CauseThe source device, such as a PC graphics card, or laptop, cannot read the EDID information from the display. As a result, in some cases the PC will not output any video signal.

While hot plug detection is supported for DVI, HDMI, and DisplayPort, EDID communication problems can arise from inconsistencies in the implementation of HPD signaling between devices from different manufacturers. This frequently becomes an issue for professional integration, since the ability to switch digital video signals is a necessity.

Possible CauseA PC cannot read the EDID information, so it defaults to a standard resolution, such as 640x480. If the user subsequently attempts to manually set the resolution to match the display, some graphics card drivers may enforce the lower default resolution and create a scrolling/panning desktop without actually changing the video resolution.

The PC is able to read the EDID information, but the graphics card limits the output resolution to XGA 1024x768, a resolution most displays can accommodate, ensuring a usable image and reducing the likelihood of no image being displayed. If this does not match the native resolution of the display, fonts will likely appear to be abnormally large, small, or fuzzy.

The PC is connected to multiple displays with different native resolutions. Since it can only read EDID from one display, the output will be mismatched in resolution with all other displays, resulting in less than optimal image quality, or no image displayed at all. This issue is a common occurrence in professional systems when video signals need to be distributed or routed to multiple displays.

Software such as Extron EDID Manager can be used to help troubleshoot possible compatibility issues between the display device and the source. EDID Manager is available as a free download from Extron"s Web site, www.extron.com. It is a useful software tool that allows you to read the display"s EDID and determine whether a graphic card and the display device may be experiencing EDID handshake problems.

AV systems typically comprise several remotely located displays and often include multiple source devices. It is important to realize this can potentially contribute to EDID-related issues. The necessity to switch, distribute, and route signals from sources to displays presents a considerable challenge in terms of ensuring proper EDID communications and therefore reliable system operation.

For example, systems that employ RGBHV-based distribution have no means of passing EDID information from the display to the source. This could become problematic in system designs where laptops and computers with expectation of seeing EDID are connected into the system. Since EDID information is not being provided to these devices, some of the aforementioned EDID communication issues may occur.

Extron products include features to help prevent or solve many of them by properly managing EDID communications between sources and displays in AV systems. These features provide automatic and continuous EDID management with attached source devices, ensuring proper power-up and reliable output of content.

EDID Emulation is a feature of many Extron DVI and HDMI products, including switchers, distribution amplifiers, and matrix switchers. It maintains constant EDID communication with source devices by providing pre-stored EDID information for various signal resolutions. A user can select the desired signal resolution, and then the corresponding EDID block is conveyed to all attached source devices. This EDID information is constantly available to the sources, even in a switching application where inputs are regularly selected and de-selected. The output of the sources should match the native resolution of the intended display device.

EDID Minder® is an advanced, Extron exclusive technology for EDID management. It encompasses EDID Emulation, but also incorporates an additional level of "intelligence." Extron products with EDID Minder® can communicate with the display device, and automatically capture and store EDID information from the display. See Figure 3. This captured information can then be used as the reference EDID for the sources. EDID Minder® is a standard feature in most Extron DVI and HDMI extenders, switchers, distribution amplifiers, and matrix switchers, as well as products that incorporate DVI or HDMI switching.

The functional role of a given product as a distribution amplifier, switcher, or matrix switcher determines the complexity of EDID Minder® implementation. Matrix switching environments represent the most difficult EDID management situation, with simultaneous EDID communications required for multiple inputs and outputs. The displays connected to the outputs are very likely to be of different models and native resolutions. The EDID information between them is different and needs to be conveyed to the source devices. Proper EDID management within the system is crucial to consistent and reliable operation.

Extron HDMI and DVI matrix switchers with EDID Minder® achieve this by managing EDID communications for each input/output tie. EDID Minder® first analyzes the EDID for all displays connected to the system, applies a complex algorithm to determine a common resolution, refresh rate and color space, and then uses the EDID protocol to set up the input sources. This powerful convenience feature simplifies system setup for the integrator, helps ensure consistent and reliable image display, and makes system operation virtually transparent to the end user.