How to force output to monitor with invalid EDID?

A fairly old 27" tv stopped detecting signal via my pc's display port, but kept working on vga. It is dual-booting windows 10 and ubuntu. It shows no BIOS screens, but once ubuntu starts loading, it would detect and output a signal, albeit the wrong resolution.

From ubuntu's logs I found that the EDID was not valid, but ubuntu was guessing an output mode and trying anyway. The BIOS and Windows don't apparently do that if they don't get an EDID, and output no signal at all. So I'm stuck with crappy vga for running windows 10.

Under linux, fixing the problem was a simple matter of a few lines in terminal to add another output mode to switch to. All I can find from Microsoft is some complex stuff about creating an .inf file with data from the tv's manufacturer. That should not be necessary.

You may need to use hardware:

Amazon.com: kwmobile HDMI EDID Manager to audio and video control: Musical Instruments

I don't think VGA sends EDID information anyway. That is only done with digital connections.

You probably need to install an INF file to indicate to Windows the required data for resolution, scan frequencies etc. Whilst these INF files are generally available for PC monitors, not for TVs.

Microsoft is correct you would have to make your own INF file. These are just plain text files so not too difficult to mod one for something else with the correct values put in for your TV.

Manufacturers data and Notepad should do it. This seems to be essentially the same as using Linux by the sound of it, so why the big problem. Surely you know how to use Notepad.

EDID does work on VGA connections - that's where DDC and EDID started.

Depending on your graphics card there may be tools available to override the EDID without manually creating the INF file - such as Custom Resolution Utility (CRU) .

Helmut said:

Manufacturers data and Notepad should do it. This seems to be essentially the same as using Linux by the sound of it, so why the big problem.

The big problem is it's an old TV and the manufacturer's data may not exist; but also should be a moot problem as I didn't need manufacturer's data to fix it using xrandr in linux.

kozzm0 said:

A fairly old 27" tv stopped detecting signal via my pc's display port, but kept working on vga. It is duaHIl-booting windows 10 and ubuntu. It shows no BIOS screens, but once ubuntu starts loading, it would detect and output a signal, albeit the wrong resolution.

From ubuntu's logs I found that the EDID was not valid, but ubuntu was guessing an output mode and trying anyway. The BIOS and Windows don't apparently do that if they don't get an EDID, and output no signal at all. So I'm stuck with crappy vga for running windows 10.

Under linux, fixing the problem was a simple matter of a few lines in terminal to add another output mode to switch to. All I can find from Microsoft is some complex stuff about creating an .inf file with data from the tv's manufacturer. That should not be necessary.

How did you make monitor to work please explain

Hi there
sometimes the resolution etc can simply be fixed from the Monitors Hardware Menu -- not from Windows but from the Menu on the monitor --even if there's no handset there's usually a manual option.

Look for things like automatically adjust picture size / change resolution frequency etc etc. Have a play with it but note settings before you start.

@dacigm007
xrandr is / was the tool on Linux systems that could be used but read below on wayland.

@kozzm0

xrandr won't work on recent Linux distros once they start using Wayland rather than the old classical X- server based on XORG. For example it's quite difficult to SSH to a Linux host with a GUI desktop when wayland is (increasingly) used,

(Windows users - the Video server in Linux is referred to the X-Server -- Window managers and various GUI's e.g GNOME, KDE, MINT etc are built on top of the X-Server so you can have several GUI's at will.

Windows itself has a single GUI and operates quite differently -- info only just ignore if not interested).

Cheers
jimbo

jimbo45 said:

Hi there
sometimes the resolution etc can simply be fixed from the Monitors Hardware Menu -- not from Windows but from the Menu on the monitor --even if there's no handset there's usually a manual option.

Look for things like automatically adjust picture size / change resolution frequency etc etc. Have a play with it but note settings before you start.

@dacigm007
xrandr is / was the tool on Linux systems that could be used but read below on wayland.

@kozzm0

xrandr won't work on recent Linux distros once they start using Wayland rather than the old classical X- server based on XORG. For example it's quite difficult to SSH to a Linux host with a GUI desktop when wayland is (increasingly) used,

(Windows users - the Video server in Linux is referred to the X-Server -- Window managers and various GUI's e.g GNOME, KDE, MINT etc are built on top of the X-Server so you can have several GUI's at will.

Windows itself has a single GUI and operates quite differently -- info only just ignore if not interested).

Cheers
jimbo

I understand but can you send me step by step what you did to make it wotk

dacigm007 said:

I understand but can you send me step by step what you did to make it wotk

Hi there
I don't think this was or should have been addressed to me -- I don't have the problem -- try the OP. !!! I was just trying to explain that xrandr might not work (probably won't work) on recent Linux distros using Wayland instead of XORG.

Cheers
jimbo