CASE STUDY OF PROBLEMS CAUSED EDIDs

Fixing the nVIDIA EDID Problem

JGene

Updated 02-22-05

Originally Posted 08-15-04

 CHANGE LOG

  • 08-15-04: Original Article Posting
  • 12-04-04: Fixed grammatical errors, added my latest EDID and notes about the latest nVIDIA ForceWare drivers
  • 12-11-04: Fixed broken link of G4U1366.dat to G4U1366.zip because the Geocities upload manager rejects files with the .dat extension
  • 02-10-05: Added table of contents and updated information on write-protecting the Gefen's DVI Detective
  • 02-21-05: Added new information about nVIDIA ForceWare Beta 71.81 WHQL drivers and configuration via EnTech Power Strip.  Also added a new monitor driver for Sharp AQUOS G4U LCDs enabling 1366x768.  Changed some of the coloring scheme for better readability as well as updated the FAQ.
  • 02-22-05: Added new information about EDID design, reader and writing software using feedback from EnTech.  Slight update of font styles for heading continuity.

 TABLE OF CONTENTS

 ADDITIONAL INFORMATION 

 Problem Description 

 On the Windows platform nVIDIA cards have a unified driver design; hence all cards from the Riva TNT to the GeForce 6800 series suffer from a software bug that can cause display devices to not function at their native resolution.  This problem is caused by deficiently designed EDID software built within the display device.

 Who This Fix Applies To

 Anyone who uses a video card powered by an nVIDIA chipset and also uses the nVIDIA ForceWare reference drivers on the Windows Platform.  DVI-equipped display devices are particularly hampered by limitations caused by this software bug.

 Background Information

 Monitors and various display devices such as HDTVs and projectors may or may not have a built in piece of software called the EDID.  EDID stands for Extended Display Information Data and contains a cornucopia of display resolution and scan rate settings as well as pixel clock limits, gamma settings and other generic properties of display device.

 Unfortunately many HDTVs, older monitors and even a few newer high-resolution wide-screen monitors have improperly designed EDIDs or lack one entirely.  This lack of foresight has caused a myriad of compatibility problems ranging from overscan problems to maximum resolution issues to even simply preventing the display device from working at all.

 If EDIDs can cause these problems then why are they built into display devices at all?  EDIDs were designed to allow simple Plug ‘N Play operation when using a digital display connection.  On older analog display devices you had to load specific device drivers to obtain the maximum resolutions and frequencies that it supported.  Worse still, many times you had to manually configure your display device even after loading the proper drivers.

 Rather than having to load device drivers for your display device, the Video Electronics Standard Association (VESA) formed the basis of the EDID standard.  This standard was designed to build the design specs, resolutions and scan frequencies right into the display device itself.  The goal was that if you included a small configuration file in the hardware then you could basically skip having to use a device driver at all.  A novel idea, but unfortunately it has its pitfalls, as you will soon see below.

 nVIDIA and EDIDs

 On the Windows platform, nVIDIA’s driver design philosophy was to rigidly enforce the settings outlined by the EDID contained within the display device.  Naturally, if you have a good EDID then the Plug ‘N Play features worked well within the intentions of the VESA standard.  However if you have a poorly designed EDID, then you would be in for a disheartening surprise.  If you had no EDID, then you may not even get any video signal to display on your output device.

 Before you point the finger of blame at nVIDIA for such odd behavior from a video card, the blame should also be shared by the manufacturer of the display device.  If you are using a monitor, then you may be in luck as the manufacturer may provide a downloadable firmware update on the Internet to address the problems that the deficient EDID is causing.  However if you are an HTPC user and are having an issue with a HDTV, then you may not get any support at all. 

 I was suffering from a maximum resolution problem that cut short the resolution I should have been able to display at.  My HDTV is a Sharp LC-37G4U 37” LCD TV.  It has the built in capability of working with PCs and has a fixed pixel resolution of 1366x768.  The resolution of 1366x768 is one which is not evenly divisible by eight so you’ll have to live with 1368x768 and two pixel columns of overscan: one on the left and one on the right.  Nonetheless for whatever reason Sharp designed the EDID to have a maximum resolution of 1280x1024.

 The nVIDIA ForceWare drivers saw that maximum resolution of 1280x1024 and held me to it.  No matter what I tried to do, there was no way I could run at 1368x768.  Each time I did I would get a virtual desktop with a window of 1280x1024, which has a 5:4 aspect ratio.  I would also get 1280x768 if I tried to run at 1368x768, a 16:9 aspect ratio version of 1024x768.

 I researched this problem on the web and actually found quite a few people were suffering from this problem – and not just those with the same monitor as me.  Interestingly enough, nVIDIA did release a fix for this in the LINUX device drivers, but no fix was ever created for the Windows platform.  (The LINUX fix is to add the line IgnoreEDID = 1, or NoDDC = 1 to your driver configuration files).  I contacted nVIDIA’s customer support about the matter and here is what they had to say:

 Future drivers will enable support for non divisible by 8 displays using NVIDIA GPUs. Cannot comment on the release date of new drivers that will fix this issue.

 Linux driver policy is different than windows and probably will not change. However, in addition to working around the problem in future drivers as stated many times over. NVIDIA has informed VESA group and the CE industry of this problem with TV displays with designated *DVI-HDTV* input. Hopefully they will follow the established international standard of VESA DDC for the Plug & Play function if they are concerned with ease of PC usage with proper aspect ratio. Most importantly include SVGA/WXGA, HDTV modes, and "native panel mode" within the EDID. That way things will "just work" like any other Digital Flat Panel out there designed for computer use. Until the driver work around you will have to use the TV as Sharp primarily intended with the use of 720P / 1080i from HDTV set top box or PC.

 I will inform you when development is done to give you some clue. I have Sony VPL-HS10 HDTV projector and it has the same panel resolution and the same problem as your Sharp when trying to use max panel resolution! So we defiantly see the problem. Thanks for your patience.

 At least they are aware of the problem and are committed to releasing a fix for it.  The down side is that they have no time frame to do it.  Basically you’ll have to live with the problem until they release their driver fix at some nebulous date in the future.

 Update 12-04-04

 After nearly four months from the original posting of this article, nVIDIA finally has delivered their promise for resolution support for non-divisible by 8 resolutions.  However, there are drawbacks. 

 Depending on your graphics card you may or may not have an external TDMS timing generator.  An external TDMS timing generator is a separate chip that sits off from the graphics processor to allow custom resolutions and timings.  Video cards with external TDMS timing generators (GeForce 6800 Ultra cards) the latest nVIDIA reference drivers will allow you to create custom resolutions that are non-divisible by 8.  You can do this by pressing the Advanced Timing button in the Screen Resolution & Refresh Rates section of the ForceWare driver panel.  If your card does not have an external TDMS then you are limited to creating resolutions that are divisible by 8 and the Advanced Timing button is hidden.

 nVIDIA's explanation from the nVIDIA 66.93 ForceWare Release Notes:

 DVI timing adjustment is supported for NV3x-based cards only if they have an external TMDS, such as the SiliconImage 164. If the card uses the internal TMDS, then the [Advanced Timing] page is not accessible. However, cards with an internal TMDS can support refresh rates less than 60 Hz in this driver.

 That said, the ForceWare 67.50 beta driver had the Advanced Timing button available for me even though my GeForce 6800 GT does not have an external TDMS.  However in the Beta 67.02 drivers the Advanced Timing button is gone again.  nVIDIA did say that they planned to support DVI timing adjustment for the GeForce 6800's internal TDMS some time in the future, however that feature is obviously still in the beta stages of development.

 Nonetheless I have read that you can still create non-divisible by 8 resolutions via third-party software utilities (Power Strip).  Four months ago this was not possible.  Sadly the EDID limitations exist today just as much as they did four months ago.

 Update 02-21-05

 In the the three months since I updated this article last December, the latest nVIDIA ForceWare drivers now include the Advanced Timing feature as standard for video cards with or without an external TDMS.

 ATi and EDIDs

 Prior to using an nVIDIA card I was using an ATi Radeon 8500 Retail with 64MB of video ram.  When I used this card I had no problem setting the output resolution to 1368x768.  Granted the ATi Catalyst drivers don’t include a utility to create custom resolutions on the fly like the nVIDIA ForceWare drivers do, but nonetheless it worked on the ATi hardware.

 All I had to do to get 1368x768 was to install the video card, the drivers, create a custom resolution of 1368x768 via third-party software utility (Power Strip) and reboot.  Simple and elegant, but why don’t the nVIDIA ForceWare drivers allow this?

 Again nVIDIA’s driver design philosophy was to rigidly uphold the outlines of the EDID provided by the display device.  ATi on the other hand still uses the EDID information to generate the list of allowed resolutions; however it does not constrain you to them.  If I wanted to run my HDTV out of spec the ATi Catalyst drivers would let me as long as I agreed to the proper warnings first.

 I asked nVIDIA about this too and their main reason for enforcing the EDID and its limitations was because they wanted to protect the average consumer from frying his or her monitor accidentally.  By preventing the user from changing into display modes and scan rate frequencies which are unsupported by the EDID, they basically created the safest drivers that they could release. However the side-effect of this built-in limitation is that it ended up marooning those who had deficiently-designed EDIDs.

 The Solutions

 Any of the below solutions will work equally well, however only the last one is within your own control.  Waiting for a software patch from nVIDIA or your display device’s manufacturer is a feasible option only as long as you are willing to live with the issued caused by the faulty EDID.

  • Contact your display device manufacturer and obtain an updated firmware that addresses the EDID problems
  • Wait for the device drivers from nVIDIA that can address EDID-related issues
  • Overwrite the EDID on your display device and or use a hardware device to work around the issue caused by the faulty EDID

 Update 02-21-05

 After six months since the creation of this article, the nVIDIA EDID bug as limited by the drivers is finally coming to a close. The most recent ForceWare drivers that I tried, Beta 71.81 WHQL, allow you to create resolutions beyond the borders of the EDID data. However the included custom resolution and timings generator will not yet allow you to create and adjust resolutions that are not evenly divisible by eight. Despite that limitation I was able to create a custom resolution of 1368x768 but only with partial success.

 Let me reiterate: to say that I had mixed results is at best an understatement—sometimes I would wind up with 1368x768 and other times I would end up with the same side-scrolling desktop that I had when I originally wrote this article. Thankfully we are not limited to using nVIDIA’s custom resolutions and timing generator. Finally after many months of toil, the same tweaks that allow ATi’s Catalyst drivers to work so well, you can now do with nVIDIA’s latest ForceWare drivers—or at least in the Beta 71.81 WHQL drivers. As of now you can use a third-party custom resolution generator, my personal favorite is Power Strip.

 New ForceWare Drivers From nVIDIA

 The following are the steps in order to create a custom resolution of 1366x768 in Power Strip as well as set up Windows to use the resolution. 

 What You Need

 Implementation

  1. Open the nVIDIA Screen resolutions and refresh rates fly out tab in the nVIDIA ForceWare drivers
  2. Uncheck Hide Modes that this monitor cannot support and click Apply
  3. Go to Digital Flat Panel Settings and select Display adapter scaling and click Apply
  4. Start Power Strip
  5. From the task bar, right click on the icon and select Display Profiles->Configure...
  6. Click on the Advanced timing options... button
  7. Click on the Custom resolutions... button
  8. Create a new custom resolution with the following timings:

Horizontal Geometry
Active - 1366 pixels
Refresh rate - 49Hz
Front porch - 38 pixels
Sync width - 184 pixels
Back porch - 220 pixels
Polarity: Negative

Vertical Geometry
Active - 768 pixels
Refresh rate - 61Hz
Front porch - 3 lines
Sync width - 6 lines
Back porch - 29 lines
Polarity: Negative

  1. Click on the Add new resolution button
  2. Click OK to try the new resolution
  3. Click Yes to keep those settings and return to advanced timing options
  4. Change the Vertical geometry Refresh Rate to 60.216Hz. and click Apply, then OK
  5. Click OK and close Power Strip

 If the above steps worked for you then you have a working desktop resolution of 1366x768. If not then try the same steps again or perhaps the drivers still have some bugs to be worked out—if all else fails try newer drivers and see if that works. Once you have your working desktop resolution you aren’t out of the thicket yet! You now need to create a custom monitor driver in order to unlock your new custom resolution for screen savers and video games.

 Power Strip has its own built in monitor driver wizard (see Monitor Information in Power Strip). Alternatively you can use my own custom Sharp G4U LCD driver. Remember to disable WHQL support because my driver is not certified and you will have to acknowledge that fact in order to install it. Simply change your driver from the Microsoft default of Standard Plug ‘N Play monitor to your own custom driver and you are done. You may need to reboot your PC in order to see the new resolution in screen savers and video games.

 If you would still like to try to craft your own EDID to fix resolution problems as well as other issues then you have two methods to choose from. 

 Information on Crafting an EDID

 Below are two additional methods to solving the EDID problem on nVIDIA cards.  One is for display devices featuring write-protected EDIDs and the other is for display devices which do not have that limitation.  Before you continue I should mention that nVIDIA just recently released a ForceWare driver set (61.76) which addressed a problem that prevented monitors from running at resolutions which had a scan rate frequency less than 60Hz.  Originally this appeared to be an EDID problem but luckily nVIDIA fixed that issue and for most people it is no longer a problem.

 EDID Design Utilities and Readers

 At the request of several others over the past few months the ViewSonic EDID Utility is not the only EDID software available. Raylar's Phoenix EDID Designer is another good utility to help create and manage EDIDs. The Phoenix EDID Designer is newer than the ViewSonic EDID Utility and appears to have a better graphical user interface (GUI). Both will work just as well so try both and see whichever one you like best. My personal favorite is still the ViewSonic EDID Utility and it is the one that I created my new EDID.

 If you would like to view your monitor’s information without having to decipher the EDID data then EnTech’s MonInfo utility. In addition to being able to parse the EDID data it also has the additional ability of decoding the CEA/EIA-861B EDID extension blocks.

 Origin of the EDID Writing Software

 The EDID Writing software that this article uses can trace its roots to the DVI_Recover utility that was created by nVIDIA for Dell users who were experiencing monitor failures when using the DVI port. Approximately a year ago there was an issue that caused the EDID of the host monitor to become corrupted and would effectively prevent the monitor from exiting the Power-Save state. The DVI_Recover utility restores the old EDID and replaces the corrupted one. Once finished it flips a bit to make the EDID write-protected.

 EnTech, the makers of Power Strip, contacted me with more information about the EDID writing software to further clarify its source and use:

 The Dell distributed "EDID writer" is for nVIDIA cards only. It requires an EEPROM in the monitor/TV that conforms to the VESA 1.0 E-EDID EEPROM Standard, and because the software communicates with that EEPROM over the I2C bus, and because each GPU has a proprietary set of I2C ports, the nVIDIA DDCW.EXE program naturally only works with nVIDIA cards.

 I can personally attest to the fact that the DDCW program will NOT work with an ATi card, or at least it did not work with my ATi Radeon 8500. If you have an ATi card then you’ll have to contact ATi and request them to craft an EDID writer or use some other hardware device that conforms to I2C protocols and can write EDIDs.

 Additional Notes

 I must also mention that oddly enough, the ForceWare Beta 71.81 WHQL drivers in combination with my own monitor device driver do not allow directly access to the EDID. Using the DDCW program and also the ViewSonic EDID Utility I receive a device read error. In contrast the Phoenix EDID Designer can still extract the EDID but only if it was previously stored in the registry. I do not have any explanation as to why I receive a device read error but my best guess would be that it is probably a device driver issue—after all I am using a beta video card driver.

 I could probe more into the issue but since I know that Sharp write-protected on my LCD TV and I cannot overwrite it in addition to the fact that I already have a working fix, pushing onward is at best a dubious goal. More than likely the next non-beta driver release will once again allow direct access to the EDID.

 Disclaimer

 Below are several steps to designing your own EDID and overwriting the one in your display device or bypassing it entirely.  Modifying your EDID is very likely to void your warranty and or damage your monitor in the process.  I would NOT recommend anyone do the following unless you absolutely know what you are doing and or have someone with you to guide you through the process.

 Solution For Monitors Without Write Protected EDIDs

 If your display device does not have a write-protected EDID then you can simply overwrite your bad EDID with a good one.

 What You Need

 Implementation

  1. Download the ViewSonic EDID Utility and make a copy of your display device’s EDID.  If your display device has no EDID to start then try to obtain one from another monitor and use it as a guide to design your own.
  2. Modify your display device’s EDID until it supports the resolutions you need it to.  Beware that you can damage your monitor by running it out of spec!  Pay close attention to the pixel clock settings and the maximum refresh rate settings.
  3. Extract the EDID hex code from the data file that you created your new EDID via the ViewSonic EDID Utility.  You will need to format it into a text file which can be read by the EDID writer program.  Use the NEC EDID included in the zip file of the EDID Writer as a guide.
  4. Create an identical copy of your existing unmodified EDID just in case the one you created does not work.  Format the EDID into a similar file which matches the NEC EDID template.
  5. Create a dos bootable disk and stick your backup EDID and the EDID Writer on the same disk.  If you cannot fit the EDID writer software and your backup EDID on the bootable disk then just stick the files on another floppy.  It only helps you save time if you can keep everything you need on the same floppy.
  6. Read the ReadMe.txt included in the EDID writer software.  Understand how to use the DDCW program and know that you can still use it to flash a blind monitor in the event that the EDID you created is bad.
  7. Use the DDCW program to verify that the original EDID on your target display device is the same as the one that you created to match the NEC EDID template.  If it does NOT match, then it’s time to go back and see what you did wrong.  There’s no point in overwriting the EDID in your display device without a working backup of your existing EDID.
  8. Use the DDCW program to overwrite the EDID in your display device with the file you created matching the NEC EDID template.
  9. Reboot your PC.

 If you followed the above nine steps then you should have resolved your problem.  If not, then go back and rewrite your EDID and try again.  It may take several revisions of the EDID before you get one that you like so be prepared to recursively tweak your EDID.

 In the event that your display device goes black, boot your PC with your dos bootable disk and the backup EDID you created.  The PC will still boot even if you can’t see anything on the monitor.  Use DDCW to reprogram the display device back to the original EDID.

 Solution For Monitors With Write-Protected EDIDs

 There are actually two subsections for this fix.  There is the simple way and the more advanced version.  The simple way should work but has more stringent requirements for the source monitor from which you would obtain a working EDID from.  The alternative is a more advanced solution and requires you to create your own working EDID to use.

 What You Need

  • Gefen’s DVI-Detective
  • Additional DVI-I cable to connect to your PC to act as an intermediary between the Gefen DVI-Detective and your display device
  • Spare monitor without a write-protected EDID for programming the Gefen DVI-Detective
  • EDID Utility and Writing Software (Advanced Fix Only)

 Implementation: Simple Fix

  1. Find a source monitor with the same type of connection as your target display device.  If you’re trying to solve a problem on an analog monitor then you’ll need an analog monitor for the source EDID.  Similarly you’ll need a digital monitor for a digital display device.  This monitor will need to have the capability to run at or greater than a resolution and scan rate for which the EDID on your target display device does not have.  Example your target monitor’s EDID monitor only supports 800x600@60Hz and your source monitor has the ability to run 1024x768@85Hz.  If you do not have a source monitor with a similar connection then proceed to the Advanced Fix section.
  2. Read and follow Programming and Operational Instructions for Gefen’s DVI-Detective below.
  3. Note: One of the drawbacks of Gefen’s DVI-Detective is that it reprograms itself to the EDID it pulls from the DVI-Out port each time it receives power from the PC via DVI-In.  If you buy two Gefen DVI-Detectives then you can use the other as a backup and flash your working model if it gets accidentally flashed back to the old EDID.

 Implementation: Advanced Fix

  1. Just as with the Simple Fix, you will still need a source monitor however this time you do not need it to be of the same type.  Since you are not going to use the source monitor’s EDID you can use an analog monitor to temporarily store the EDID of a digital display device while you use it to program the Gefen DVI-Detective.
  2. Read the instructions on creating an EDID and flashing it to a monitor as described in Solution For Monitors Without Write Protected EDIDs.
  3. Create a backup EDID of the source monitor.
  4. Use the EDID writer to program the source monitor with the EDID of your target display device.
  5. Program Gefen’s DVI-Detective with the EDID stored the source monitor.
  6. Use the EDID writer to reprogram the source monitor to its’ original EDID.
  7. Reconnect Gefen’s DVI-Detective to your target display device using the instructions from Programming and Operational Instructions for Gefen’s DVI-Detective below.
  8. Note: One of the drawbacks of Gefen’s DVI-Detective is that it reprograms itself to the EDID it pulls from the DVI-Out port each time it receives power from the PC via DVI-In.  If you buy two Gefen DVI-Detectives then you can use the other as a backup and flash your working model if it gets accidentally flashed back to the old EDID.
  9. Reboot your PC.

 Programming and Operational Instructions for Gefen’s DVI-Detective

  1. Plug in the 5V power plug then connect the Gefen DVI-Detective via DVI-Out to the source monitor with the good EDID.
  2. Wait until the LED stops flashing and stays solid RED.
  3. Disconnect the Gefen DVI-Detective from the source monitor and remove the 5V power plug.
  4. Plug in the 5V power plug then connect the Gefen DVI-Detective to the PC via DVI-In.  DO NOT HOOK UP THE TARGET DISPLAY DEVICE VIA DVI-Out AT THIS POINT.
  5. Wait until the LED stops flashing and stays solid RED.  This step is necessary because when the Gefen DVI-Detective senses the DVI-In plug has changed it tries to recapture the EDID from anything that is plugged in to the DVI-Out port.  Unless your target output device has the proper EDID the Gefen DVI-Detective will pull the old EDID and overwrite your new one.  Once the LED has stopped flashing, the DVI-Detective has stopped trying to locate a new EDID and will stick with your good one.
  6. Plug in the target display device to DVI-Out on the Gefen DVI-Detective.
  7. Warning: If the DVI-Detective looses power, unplug the output device from DVI-Out or the DVI-Detective will revert back to the old EDID the next time it receives a video signal from the PC via DVI-In.

 Write-Protection Instructions for Gefen’s DVI-Detective

 After establishing that you have the correct EDID stored on the Gefen DVI-Detective you can write-protect it.  Write-protecting the EDID will prevent the Gefen DVI-Detective from relearning the old EDID as well as eliminate the need to continuously use the 5V power supply.

  1. Use a Philips-head screwdriver to remove the two lock screws on the bottom of the Gefen DVI-Detective.

  1. On the DVI-In port, use a pair of needle-nose pliers or a small socket wrench to unscrew the stand offs screws.  Slide the top half of the Gefen DVI-Detective away from the bottom half to open it.

  1. Once inside the Gefen DVI-Detective, remove the EEPROM chip from its socket by pulling on it straight upwards.  This chip contains the core logic of the Gefen DVI-Detective to reprogram itself each time it receives a 5V power source and EDID from the DVI-Out connector.

 After removing the logic EEPROM, reassemble the Gefen DVI-Detective in reverse order and attach it to your monitor and video card.  Do not attach the 5V power supply unless you want to reprogram the Gefen DVI-Detective with your new EDID again.  Since the logic EEPROM has been removed the LED will not glow when in use.  The EDID that is stored on the Gefen DVI-Detective is now write-protected.

 Gefen uses a MICROCHIP 24LC21 EEPROM to store the EDID.  The socket chip is a MICROCHIP 12C509A which some of you may recall that is the same model that many use for "chipping" Sony Playstations.

 EDID Repository

 Here is the feature list for the EDID that I have written to allow support for 1366x768 for Sharp G4U LCDs.  You can open it using the ViewSonic EDID Utility.

  1. Standard Timing Identification

  • 640 X 400 @60Hz
  • 640 X 480 @85Hz
  • 848 X 477 @60Hz
  • 800 X 600 @85Hz
  • 1024 X 768 @85Hz
  • 1280 X 720 @60Hz
  • 1280 X 1024 @60Hz
  • 1368 X 770 @60Hz

  1. Detailed Timing / Descriptor Block 1: 1366x768

    Pixel Clock: 87.75 MHz

    Horizontal Image Size: 0 mm
    Vertical Image Size: 0 mm
    Refreshed Mode: Non-Interlaced
    Normal Display - No Stereo

    Horizontal:
    Active Time: 1366 pixels
    Blanking Time: 442 pixels
    Sync Offset: 38 pixels
    Sync Pulse Width: 184 pixels
    Border: 0 pixels
    Frequency: 48.53 KHz

    Vertical:
    Active Time: 768 lines
    Blanking Time: 38 lines
    Sync Offset: 3 lines
    Sync Pulse Width: 6 lines
    Border: 0 lines
    Frequency: 60.22 Hz

    Digital Separate
    Horizontal Polarity (-)
    Vertical Polarity (-)

  2. Detailed Timing / Descriptor Block 2: 1280x768

    Pixel Clock: 81.00 MHz

    Horizontal Image Size: 0 mm
    Vertical Image Size: 0 mm
    Refreshed Mode: Non-Interlaced
    Normal Display - No Stereo

    Horizontal:
    Active Time: 1280 pixels
    Blanking Time: 408 pixels
    Sync Offset: 48 pixels
    Sync Pulse Width: 112 pixels
    Border: 0 pixels
    Frequency: 47.99 KHz

    Vertical:
    Active Time: 768 lines
    Blanking Time: 34 lines
    Sync Offset: 1 lines
    Sync Pulse Width: 3 lines
    Border: 0 lines
    Frequency: 59.83 Hz

    Digital Separate
    Horizontal Polarity (+)
    Vertical Polarity (-)

 I rewrote the Standard Timing Table in the EDID as well as added 1366x768 as a Detailed Timing.  I left the existing 1280x768 Detailed Timing entry in because you cannot add it to the Standard Timing Table because there is no 15:9 aspect ratio.  There was an error in the ORIGINAL EDID that supported 1280x1024@85Hz.  That resolution is beyond the supported maximum 110MHz pixel clock and results in a black screen when trying to run that refresh rate for that resolution.

 I added 848x477@60Hz but right now that is a broken feature.  What I wanted is 848x480 because it is a supported resolution listed in the user manual. I would have liked to add it to the Detailed Timing section but to do so I would have to remove 1366x768 or 1280x768. 

 The resolution of 1368x770 is actually rounded to 1368x769 in the nVIDIA ForceWare drivers.  Why the extra pixel row?  The Standard Timing Table only allows 1368 at 16:9, which yields 768.5.  The nVIDIA ForceWare drivers round 768.5 to 769 for 1368x769 resolution.

 Download Sharp G4U LCD EDID

 I also created a INF Driver for Windows XP that includes the resolution of 1366x768.  The driver is not necessary for those who create their own custom EDIDs, however if you use the nVIDIA ForceWare drivers then a monitor driver is required to extend the custom resolution of 1366x768 to screen savers and video games.  Without it you are still limited to 1366x768 only on the desktop.

 Download Sharp G4U LCD Windows XP Driver

 Frequently Asked Questions

  • Was I able to upload my new EDID into my Sharp TV?
    • No, because my EDID is write-protected and I have to use a Gefen DVI-Detective to "feed" the proper EDID to my video card.
  • How long until nVIDIA fixes this problem?
    • nVIDIA seems to have fixed this issue with the ForceWare Beta 71.81 WHQL drivers however if you still have issues then contact them directly via their technical support page.
  • Can you help me write my own EDID?
    • Yes I can.
  • Can I get a Gefen DVI-Detective with your Sharp AQUOS G4U 1366 EDID on it?
    • Yes, I can sell you one for $100 shipped.

 Credits and Acknowledgements

 The EDID utility that I included in this fix is from ViewSonic and can be found on their website.  The EDID Writing software was given to me by someone who I found off of an Internet forum. Many thanks go out to him and without the software contributions from EnTech, Raylar and ViewSonic this fix would not have been possible.

 I also extend thanks to the generous people at AVSForum for introducing me to Gefen’s DVI-Detective. Also thanks again for the multitude of suggestions to fixing this problem by people on the NVNews Forums.

 E-mail me for any comments or questions regarding this fix.

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