Zorin OS 15 boots to black screen

I have successfully installed Zorin 15 OS on my old Dell Vostro 3700 laptop and have been using it without problems for a week or more.

Booting today, the computer starts normally, showing the Dell welcome screen for f2 and f12 options and the usual grey frame comes on as Zorin starts the boot. Then the boot-finished musical chimes come on and the cursor appears. But the screen is black.

The Dell key combinations for screen brightness did not work with Zorin, so I successfully installed Gnome extensions which gave me some limited control of screen brightness. The last thing I remember doing yesterday was to install another app or extension to try out for getting a greater range of screen brightness. So I am wondering whether the new app/extension is coming on with the screen dimmed to zero. I also found the night light app which makes the screen go fainter and more red as the night progresses. This was working properly last night.

Is there a way to boot with the extensions turned off? Then I can remove the extensions and try again.

Or otherwise, the problem is caused by something else ...

Any help, please? Thanks.

I have successfully installed Zorin 15 OS on my old Dell Vostro 3700 laptop and have been using it without problems for a week or more.

Booting today, the computer starts normally, showing the Dell welcome screen for f2 and f12 options and the usual grey frame comes on as Zorin starts the boot. Then the boot-finished musical chimes come on and the cursor appears. But the screen is black.

The Dell key combinations for screen brightness did not work with Zorin, so I successfully installed Gnome extensions which gave me some limited control of screen brightness. The last thing I remember doing yesterday was to install another app or extension to try out for getting a greater range of screen brightness. So I am wondering whether the new app/extension is coming on with the screen dimmed to zero. I also found the night light app which makes the screen go fainter and more red as the night progresses. This was working properly last night.

Is there a way to boot with the extensions turned off? Then I can remove the extensions and try again.

Or otherwise, the problem is caused by something else ...

Any help, please? Thanks.

khs10uk, often when people install several packages, they tend to uninstall a package along the way while they are at it.
Had you done any removals or a "sudo apt-get autoremove" last night when you were doing installations?

Many thanks, Aravisian. I eventually discovered how to boot into Zorin while holding down the shift key and one option started the OS. In naff graphics, I was able to find the most recent extension that I had added the previous evening, and having removed it, Zorin booted normally and gave me the usual (visible) screen. Just a guess, but maybe that extension was starting with the default screen brightness set to zero.

Many thanks, Aravisian. I eventually discovered how to boot into Zorin while holding down the shift key and one option started the OS. In naff graphics, I was able to find the most recent extension that I had added the previous evening, and having removed it, Zorin booted normally and gave me the usual (visible) screen. Just a guess, but maybe that extension was starting with the default screen brightness set to zero.

Ah, good that you got it sorted out. Sounds like that extension may be depreciated or broken.