thanks … err I know it now. 
I could “rsync” back, before committing that crime … oh, maybe not 
If you have a backup, go for it of course.
If it is a fresh install, just reinstall Manjaro properly and install video drivers properly.
But is the above the same as ?:
sudo mhwd -a pci nonfree 0300
yeah well… did some cleanup and:
[alpine2powerhost bin]# mhwd -a pci nonfree 0300
> Using config 'video-nvidia' for device: 0000:02:00.0 (0300:10de:11b4) Display controller nVidia Corpo
ration GK104GL [Quadro K4200]
> Installing video-nvidia...
Sourcing /etc/mhwd-x86_64.conf
Has lib32 support: true
Sourcing /var/lib/mhwd/db/pci/graphic_drivers/nvidia/MHWDCONFIG
Processing classid: 0300
Sourcing /var/lib/mhwd/scripts/include/0300
Processing classid: 0302
:: Synchronisiere Paketdatenbanken...
core ist aktuell
extra ist aktuell
community ist aktuell
multilib ist aktuell
Löse Abhängigkeiten auf...
Suche nach in Konflikt stehenden Paketen...
Pakete (4) lib32-nvidia-utils-460.32.03-1 linux419-nvidia-460.32.03-3 linux59-nvidia-460.32.03-1 nvi
dia-utils-460.32.03-1
Gesamtgröße der installierten Pakete: 472,26 MiB
:: Installation fortsetzen? [J/n]
Prüfe Schlüsselring...
Prüfe Paketintegrität...
Lade Paket-Dateien...
Prüfe auf Dateikonflikte...
Überprüfe verfügbaren Festplattenspeicher...
:: Verarbeite Paketänderungen...
Installiere nvidia-utils...
==> If you run into trouble with CUDA not being available, run nvidia-modprobe first.
Optionale Abhängigkeiten für nvidia-utils
gtk3: nvidia-settings [Installiert]
xorg-server-devel: nvidia-xconfig
opencl-nvidia: OpenCL support
Installiere lib32-nvidia-utils...
Optionale Abhängigkeiten für lib32-nvidia-utils
lib32-opencl-nvidia
Installiere linux419-nvidia...
In order to use nvidia module, reboot the system.
Installiere linux59-nvidia...
In order to use nvidia module, reboot the system.
:: Starte post-transaction hooks...
(1/6) Creating system user accounts...
Creating group nvidia-persistenced with gid 143.
Creating user nvidia-persistenced (NVIDIA Persistence Daemon) with uid 143 and gid 143.
(2/6) Reloading system manager configuration...
(3/6) Arming ConditionNeedsUpdate...
(4/6) Updating module dependencies...
(5/6) Updating Kernel initcpios for Nvidia-DRM...
==> Building image from preset: /etc/mkinitcpio.d/linux419.preset: 'default'
-> -k /boot/vmlinuz-4.19-x86_64 -c /etc/mkinitcpio.conf -g /boot/initramfs-4.19-x86_64.img
==> Starting build: 4.19.167-1-MANJARO
-> Running build hook: [base]
-> Running build hook: [udev]
-> Running build hook: [autodetect]
-> Running build hook: [modconf]
-> Running build hook: [block]
-> Running build hook: [keyboard]
-> Running build hook: [keymap]
-> Running build hook: [filesystems]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-4.19-x86_64.img
==> Image generation successful
==> Building image from preset: /etc/mkinitcpio.d/linux419.preset: 'fallback'
-> -k /boot/vmlinuz-4.19-x86_64 -c /etc/mkinitcpio.conf -g /boot/initramfs-4.19-x86_64-fallback.img -
S autodetect
==> Starting build: 4.19.167-1-MANJARO
-> Running build hook: [base]
-> Running build hook: [udev]
-> Running build hook: [modconf]
-> Running build hook: [block]
-> Running build hook: [keyboard]
-> Running build hook: [keymap]
-> Running build hook: [filesystems]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-4.19-x86_64-fallback.img
==> Image generation successful
==> Building image from preset: /etc/mkinitcpio.d/linux59.preset: 'default'
-> -k /boot/vmlinuz-5.9-x86_64 -c /etc/mkinitcpio.conf -g /boot/initramfs-5.9-x86_64.img
==> Starting build: 5.9.16-1-MANJARO
-> Running build hook: [base]
-> Running build hook: [udev]
-> Running build hook: [autodetect]
-> Running build hook: [modconf]
-> Running build hook: [block]
-> Running build hook: [keyboard]
-> Running build hook: [keymap]
-> Running build hook: [filesystems]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-5.9-x86_64.img
==> Image generation successful
==> Building image from preset: /etc/mkinitcpio.d/linux59.preset: 'fallback'
-> -k /boot/vmlinuz-5.9-x86_64 -c /etc/mkinitcpio.conf -g /boot/initramfs-5.9-x86_64-fallback.img -S
autodetect
==> Starting build: 5.9.16-1-MANJARO
-> Running build hook: [base]
-> Running build hook: [udev]
-> Running build hook: [modconf]
-> Running build hook: [block]
-> Running build hook: [keyboard]
-> Running build hook: [keymap]
-> Running build hook: [filesystems]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-5.9-x86_64-fallback.img
==> Image generation successful
(6/6) Updating the desktop file MIME type cache...
nvidia-utils: Installations-Grund wurde auf "Ausdrücklich installiert" gesetzt
lib32-nvidia-utils: Installations-Grund wurde auf "Ausdrücklich installiert" gesetzt
linux419-nvidia: Installations-Grund wurde auf "Ausdrücklich installiert" gesetzt
linux59-nvidia: Installations-Grund wurde auf "Ausdrücklich installiert" gesetzt
xorg configuration file: '/etc/X11/mhwd.d/nvidia.conf'
> Successfully installed video-nvidia
sounds good?
Seems good. Linux 5.9 reached its end of life, so upgrade to (e.g.) 5.10: sudo mhwd-kernel -i linux510, and if everything works, remove the old one: sudo mhwd-kernel -r linux59.
thank orr the little hint.
And what about linux 419? I never put so much attention on the kernel since I am running on not-so-modern machines 
And how?
I would use the architect. Choosing nvidao proprietary there - or choose nothing and do it by hand? 
To reinstall download a normal ISO, then install, reboot, update the system, install LTS Kernel from Manjaro Settings GUI tool, reboot on that LTS Kernel, remove EOL Kernel (probably 5.9 from the ISO, again from the GUI tool), keep only the LTS Kernel, reboot. When all is good go to Manjaro Setting GUI tool, check Hardware menu if the Nvidia driver is properly installed.
I love this manjaro thang BTW. It’s my first weeks you know.
I had too much trouble with funtoo and gentoo, sooooo I came.
Anyone in this thread using Gentoo? 
this works. Thank you+
thanks a lot for this. been using it on two machines already:
sudo mhwd -a pci nonfree 0300
it tends to install the 390 version of NVIDIA firmware, though. It’s outdated soon, isn’t it?
Would this work?:
sudo mhwd -a pci nonfree 0400
Then specify which of both nvidia available driver you want in your MHWD command.
Also “it tends to” no, it installs this or that, it doesn’t “tends to” do random things.
Why 0400?
Here you can see the config as I want it. On the other machine the mhwd somehow installed the 390 driver. Probably, because I have an older card in there. But is there any way to control this a bit more? Which driver of the two (video-nvidia-390xx vs video-nvidia) mhwd selects?
or: what does the 300 mean?
[powerhost jaro]# mhwd -li
> Installed PCI configs:
--------------------------------------------------------------------------------
NAME VERSION FREEDRIVER TYPE
--------------------------------------------------------------------------------
video-nvidia 2020.11.30 false PCI
Warning: No installed USB configs!
[powerhost jaro]# mhwd -l
> 0000:02:00.0 (0300:10de:11b4) Display controller nVidia Corporation:
--------------------------------------------------------------------------------
NAME VERSION FREEDRIVER TYPE
--------------------------------------------------------------------------------
video-nvidia 2020.11.30 false PCI
video-nvidia-390xx 2020.11.30 false PCI
video-linux 2018.05.04 true PCI
video-modesetting 2020.01.13 true PCI
video-vesa 2017.03.12 true PCIIf ti doesn’t install the latest drivers (video-nvidia which provides drivers 460.xx) then your card is not compatible with it.
MHWD will select video-nvidia if it is compatible.
As said, if you want to specify a driver then do it in the MHWD command.
Thats what I am trying to do here.
But its just little tweaking while the systems works fine. I think I got it for now.
THANKS
I mean WHY 0400 where did you get that from?
If you want to specify a driver do not use this command for auto installation.
Surprised nobody sent you there but you need to read a little Configure Graphics Cards - Manjaro
OK.
That was guessing. I’ll read that HowTo, clearly. I think everything has been said. And I have learned a lot.
I read the installation howto, though. At least 