I love Ubuntu, I really do but sometimes its just a pain. I bought a Packard Bell Easynote TK37 which has a notoriously poorly supported Intel graphics card, the Intel GMA4500.
There are several ways to get around the no backlight issue in ubuntu depending on how urgently you need it but I’ve found a fix which seems to be largely undocumented online.
Use a torch to view your display and run the below in a terminal window and it will turn on your backlight again.
sudo setpci -s 00:02.0 F4.B=7F
You can add this as a bootscript to fix it for good, that’s what I did, but this seems to have fixed all my issues. Good luck with any you have!
Note: You can also edit grub on boot but you will not have any resolution beyond 1024×768, all you have to do is add nomodeset and you will have a bootable Ubuntu.