Zorin 16.1 - Black Screen After Login & Brightness control is not working

Have you tried rolling back to the previous kernel to test if the black screen remains?
Tap the esc or the tab key after seeing yuor Motherboard splash screen to access the grub menu, then choose Advanced Options for Zorin
Arrow key down to the previous earlier kernel and hit enter to boot from it.
If it works with no black screen, lock in the kernel: