Like many others I updated my Manjaro system and ended up with the dreaded Failed to start Load Kernel Modules and Failed to start Light Display Manager.
I did some searching and found several “fixes” that involved chroot and such with Live system. I was not able to resolve the situation using any of them because for whatever reason, even though I could browse the web, pacman said I had no internet, so I started digging a little deeper. Of course I ran a crossed the notation of the update removing older Nvidia drivers. A little testing proved that I could get into a tty with Ctrl + Alt + Fx (I used F3) and log in.
Knowing it is broken Nvidia causing the issue, I tried first to run sudo mhwd -a pci nonfree 0300 to install the latest Nvidia drivers. This failed because of dependency issues caused by other Nvidia related packages.
Long story short, I ended up using pacman -R … to uninstall pretty much anything Nvidia (sorry, I forget the package list). Once those were uninstalled I ran the sudo mhwd -a pci nonfree 0300 again. Like magic it zipped along and installed the latest Nvidia package and those dependencies that matched current kernel.
After a sudo restart all was well. I hope that this experience can help some other user with the same issues get their system back up and running.