The computer is a mid-2010 MacbookPro with 16GM RAM and a 250GB SSD. I installed 24.04 via USB stick written using BalenaEtcher.app.
First Approach
I instructed the installer to install a minimal desktop, not to include 3rd party drivers, and to use the entire disk for the Ubuntu installation. After install, the WIFI adapter was not detected and so I followed the instructions I found on YouTube for the 22.04 release; namely: https://youtu.be/Fpqh6DNj4wA?si=eIjef1qd3dhNxHBc&t=625
sudo apt-get purge bcmwl-kernel-source
sudo apt-get install firmware-b43-installer
I must have done a "soft" reboot from the Ubuntu menu as that was a required step after which the Wifi adapter started working.
I turned the computer off and on, however, and I could only get to the Grub menu after that. If I select the Ubuntu default option, "Try or install Ubuntu" (??) the next screen was just black, with one white underscore cursor toward the upper left that was not blinking.
I was able to edit the grub entry, adding in "nomodeset" as detailed in another answer on this site - but this did not have any effect.
Second Try
I tried the install again with a different approach. This time, I installed MacOS Mountain Lion, rebooted with the Ubuntu 24.04 USB stick and installed, indicating to "Install alongside MacOS". I also asked it to install the 3rd party drivers. To my surprise, it installed all the files right into the same filesystem! Also, the Wifi worked out of the box.
In any case upon powering off and on, the behaviour is the same. A black screen and no sign of activity except for the white underscore cursor in the upper left.
I found a new symptom, however. On this black screen with the white underscore, holding down the Macbook's power button for a few seconds caused the screen to go purple and to show an Ubuntu "Loading ...." screen.
