The reverse of what you did.
sudo mhwd -r pci video-nvidia
Once you’ve done that … reboot. It may work ok.
Then look at what mhwd suggests:
mhwd -l
There are multiple nvidia series that manjaro provides. Likely your older card(s) want one of them.
[video-nvidia-390, video-nvidia-470, etc]
Okay, I rebooted and got the same thing but slightly different. Now my black screen has some nouveau error codes. They are:
[ 4.307302] nouveau 0000:01:00.0: bus: MMIO write of 80000122 FAULT at 10eb14
[ PRIVRING ]
[ 5.481859 ] nouveau 0000:0a:00.0: bus: MMIO read of 00000000 FAULT at 3e6684 [ PRIVRING]
I still have access to tty2, but it shows up on my other monitor now, the one connected to the GTX 950 (before it was on the GTX 750 Ti monitor)
What am I looking for in the output of mhwd -l?
With two Nvidia GPUs and your Monitors setup like that you will have to set Multihead as described in NVIDIA - ArchWiki
The problem that might happen in your case is that i’m not sure if the GTX 750 is supported by the latest Nvidia driver. The GTX 950 is, but you might have to go back to the video-nvidia-470xx and then set the Multihead part as described in the Arch wiki link mentioned above.
With Nouveau drivers aka video-linux the gaming will suffer greatly in performance …
I won’t swear to it but I believe the 530 driver starts it’s support at the nvidia 650 card and up. My previous card to this one was the 750 and I know I was on newer than 470 driver.
I just need to get my desktop back first… then I can try getting the NVIDIA drivers to work. But right now I don’t have an accessible desktop! How can I at least fix it to get a desktop?
When I plug in my live USB and boot with proprietary drivers I get the same thing, with the black screen.
Hi, i had a simaler problem. But I fixed it.
Mayber my thread will help you (see link).
Short answer:
at my system it was about all about the nvedia driver that wouldnt work with the intel drivers.
(i know you have an amd system, but maybe it’s the same solution (?))
In the end i had to take “ibt=off”. (search it on the search engine of your choice)
It will stop some boot option that will the system make more secure. (i am not an it expert)
How do you get there? (aks ChatGPT for a more detailed answer)
open
root/etc/default/grub
in the grub data you look for
GRUB_CMDLINE_LINUX_DEFAULT=…
and ad ibt=off
at the end it should look like this
GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash resume=UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx resume_offset=xxxx ibt=off”
save the grub data
than go the command line and write
sudo update-grub
it should update the real grub
restart your computer
everything should work fine
(hope i could help)
(for myself i cant find any option to save my data on my computer, so i hat to start from the bottom 
)
best regard from germany
maybe open suse will help or the grub menu
(you can get to the grub menu by choosing it on the bootloader - at my system it was just an empty line, but that was the grub menu)
no. this is an AMD cpu not a Intel pu
can you add on boot kernel
even with USB live manjaro or on screen boot Grub ( Press Esc or F8 to appears )
“iommu=pt”
Do I add this to GRUB_CMDLINE_LINUX_DEFAULT?
yes you have to
Okay, I added it to that and rebooted. Got the same results. (Black screen with movable cursor.)
with 2 cards nvidia , this is not possible , no support of NV dual link
only one can works
Okay, so do I just unplug one and it should work?
My main goal was to do a GPU passthrough to a VM for the GTX 950 anyways.
yes only one plugged it should works
you may get this log with iommu=pt
iommu: Default domain type: Passthrough (set via kernel command line)
...
kernel: pci 0000:0a:00.0: Adding to iommu group 26
kernel: pci 0000:00:00.2: AMD-Vi: Found IOMMU cap 0x40
kernel: AMD-Vi: Extended features (0x58f77ef22294a5a, 0x0): PPR NX GT IA PC GA_vAPIC
kernel: AMD-Vi: Interrupt remapping enabled
kernel: PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
kernel: software IO TLB: mapped [mem 0x00000000b1fb1000-0x00000000b5fb1000] (64MB)
kernel:LVT offset 0 assigned for vector 0x400For that indeed you will need later to do as @stephane explained.
To get your system booting, use just one card. Before you will add back the second one you will have to get the BusID PCI for that card and add it to the /etc/X11/mhwd.d/nvidia.conf file.
Sometimes booting with nomodeset instead of quiet helps, even without the nvidia.conf, but with multiple Monitors things will get unpredictable …
Okay I just took out my GTX 950 and the monitor plugged into it. Now, were only dealing with one monitor plugged into my GTX 750 Ti. How do I get the BusID PCI? Also, I uninstalled all NVIDIA drivers from earlier. Do you want me to reinstall them?
After booting with just one card and one monitor I got the same result. I am still able to access tty2, as mentioned earlier.
If I really need to, I can reinstall Manjaro with the open source drivers, and at least have access to a desktop. But I’ll need to know how to get the proprietary drivers working correctly.
If you boot the live USB with Proprietary Drivers, is it working?
Might want to install from TTY the video-nvidia and see if after that you can boot.
I also recommend, as in my case never gave me troubles, to enable early KMS
The quickest way to get the BusID is via Nvidia Settings, i can’t recall right now the command 
if you have a terminal or console TTY
sudo mhwd -a pci nonfree 0300No, booting from a live USB with proprietary drivers yields the same black screen.
After installing video-nvidia using
sudo mhwd --install pci video-nvidia
I got the same exact black screen.