Backlight not working on 18.04

Tried upgrading to Mate 18.04. Had a number of issues with the screen being way too dark to be even usable. You could only faintly see the desktop after booting from Live USB. I’m running ASUS FX503V with NVIDIA GeForce GTX 1050.
Tried fiddling with isolinux/grub by adding:

  • nouveau.modeset=0
  • nvidia.modeset=0
  • acpi_backlight=vendor
  • acpi_backlight= nvidia (just to see what would happen…nada)
    Interestingly, I was able to install plain Ubuntu 18.04 but it would lock up at that login screen once installed. couldn’t even drop to tty.
    Fiddled with BIOS setting
  • secure boot off
  • fast boot off
  • CSM enabled and disabled
    there is only one setting for the video card in my BIOS and all it does is change memory size from 32 to 64.
    I finally gave up and reinstalled MATE 16.04 but it was acting wonky though I was able to drop to tty and install updates as well as the latest NVIDIA Driver 396 (I figured why not…plus, I couldn’t remember what version NVIDIA driver I had working previously) Now, I’m back to a stable system with no intention (currently) to try 18.04 again.
    Anyone else have this issue? I did countless searches and tried every one of them. I guess it might have something to do with the kernel? I certainly don’t know but there was no way I could do a clean install of 18.04 (I even tried burning a DVD and booting from that). I suppose I could try upgrading through upgrade-manager. The only thing I can figure is that it’s the backlight on the laptop.