[FAILURE] Monterey on HP Compaq Elite 8300 All-In-One

[EliteMacx86]

Yeah, and I dunno why
The only slider available is "colour".

No, no. It's wrong.

Go to System Preferences>Displays. Make sure you select the Internal screen. Then just on the display tab, there should be a brightness slider present. Post a picture to confirm.

 

[HarFanG]

I looked everywhere ^^

 

[EliteMacx86]

I looked everywhere ^^

Its still the LG monitor selected. You must select the built-in screen. In addition, you must be in Display tab, not the arrangement tab

 

[HarFanG]

I know, I know...but if I play with that, I end with two black screens

 

[HarFanG]

I installed Teamviewer on autostart and launched Big Sur.

Logging in from a PC, I see that the AIO only displays a black screen, even though I can enter the password blind.

So I don't think there's a problem with the backlight.

But why does the AIO screen work properly at first, and then display nothing once the graphics drivers have been installed?

I think we need to explore this a little further, don't you?

Let's imagine a PC with a > GTX 1000: we install Windows, and once on the desktop, we install the nVIdia driver. And right after that, the screen would go black.
What would we do?

And yet another detail: the AIO screen is not “seen” by Big Sur until its own EDID is injected into the system. Why is this?
Whereas the Acer G245H is “seen” immediately...without doing anything...

 

[EliteMacx86]

But why does the AIO screen work properly at first, and then display nothing once the graphics drivers have been installed?

Have explained it before. The acceleration works when the driver loads and when the driver loads, it expects the hardware to be compatible, which is not the case here.

I think we need to explore this a little further, don't you?

EDID was modified and tested but neither the Backlight works (similar to Dell AIO) nor the display. Further tests require much time for this project.

Let's imagine a PC with a > GTX 1000: we install Windows, and once on the desktop, we install the nVIdia driver. And right after that, the screen would go black.
What would we do?

Indicates faulty drivers. So, cleanup tool and then reinstall the drivers. If that doesn't fix it, clean Windows install and even if that doesn't fix it, change the GPU. A mined card on Windows can give you black screen. A card which is failing will give you black screen. Now, what options do you have on the macOS side, considering your system is an AIO?

And yet another detail: the AIO screen is not “seen” by Big Sur until its own EDID is injected into the system. Why is this?

Cause the default EDID is not being picked by macOS. Therefore, injecting the same actual EDID gives the display but end up in black screen, which indicates some more modification is needed in terms of EDID.

Whereas the Acer G245H is “seen” immediately...without doing anything...

External monitors are supported natively for 99.99% of the time!

 

[HarFanG]

Okay.

Well, I tried to "play" with EDID editor : Analog Way EDID Editor. Nice tool ! You should give it a look !

After that, I tried every "model" (0x166A thingy) : a few ended with black screen(s), a few worked, but HQP stood black).

Right now, I did a fresh Big Sur install on another drive, and I got a nice surprise. But I need to edit this post from the "Mac" as the ss are stored on it.
Will do this in a few minutes.

 

[HarFanG]

So, I totally removed "DP" options, and used "igfxvesa" switch.
The install went fine, no display acceleration, but 1080p finally.

Obviously, the sound do not works. Obviously.

Now, I have 2 choices :
- removing "igfxvesa" switch, or
- trying to inject HQP screen EDID

No idea what's the best to do...

 

[EliteMacx86]

So, I totally removed "DP" options, and used "igfxvesa" switch.
The install went fine, no display acceleration, but 1080p finally.

Obviously, the sound do not works. Obviously.

Now, I have 2 choices :
- removing "igfxvesa" switch, or
- trying to inject HQP screen EDID

No idea what's the best to do...

Of course, the EDID thingy as the first will disable the Graphics acceleration entirely.

 

[HarFanG]

But it's the first time I got 1080p !
All the previous installs gave only 1280x1024, hmmm...

And maybe there's a path to explore with "mirroring" ? I saw it's disabled on the system info picture.

About the 2 choices, what's your bet ?