maybe a driver problem

I'm having this exact same issue (black screen + fans at full speed), discord and other things seem to be working in the background as I can still hear and talk to friends. Only way to recover is power cycle my PC. I'm using an EVGA 3090 FTW3 Ultra. Just installed the latest NVIDIA drivers as well as the latest Precision X1 which updated the firmware on my GPU. Haven't tested it yet but from the looks of this forum, Reddit, etc it doesn't look good.
 
Anyone have real any updated info on cause, and more importantly, a fix?

Seems pretty widespread don't think everyone with issues card is dieing.

Mine didn't black screen for a while but today Vegas Pro 18 crashed several times with a black screen and my Games are running weird.. I get like puases its really strange. 

I managed to complete a small render of 30 seconds to test and it didn't black screen but I'm getting weird window blending in Vegas. My scratch drive window blends with my Vegas window really weird. Games seem to run fine though. It will be fine for a few weeks then it will act weird. I might put in an RMA with EVGA becuase the shop I bought it from are absolutely useless. Its such a headache to RMA the card.. Given the current situation it will probably take ages to send it etc. I'm about to render a 1 hour video so lets see how it goes, I will report back. 

PennywiserthanU
Mine didn't black screen for a while but today Vegas Pro 18 crashed several times with a black screen and my Games are running weird.. I get like puases its really strange. 

Actually Vegas is known to be unstable.  I highly recommend on reading the reviews on steam.

Folks, if you're getting issues on all your gaming platforms, chances are it's the GPU but if it's only with a few but majority are fine, it's most likely not the GPU.  I'm not singling out that a GPU might be dying but the chances are that it's most likely software related. 
 
One of the hardest things to do is get a variety of hardware/software to get along hence why apple is pretty successful on their end i.e. iphone/ipad, etc.

Updating. I read a lot of posts and tried various things. But ultimately I decided that upgrading my PSU was the best option to try to fix the issue. I went from 850w (which should be enough) to 1000w. When rebooted I was forced to reset a bunch of programs after the PSU switch. Long story short this led me to decide to update the Motherboard BIOS (because a couple of update releases mentioned GPU stability/ performance), which I always read not to do unless there is something wrong. However, the end result of this was that my in-game wattage for Apex Legends went from averaging about 330 W (every value in this game fluctuates a lot) to 240 W. In Halo Infinite it went from a consistent 325 W to 270 W. Temperatures didn't change. For me, the black screen/fan issue only seemed to happen in Apex, which would actually have spikes of up to 395 Watts. If not for the amount of effort, I'd put the old PSU back in and see if the wattage changes stay the same. However, I do not think a higher wattage PSU decreases the wattage output of the GPU. Anyway, I guess my point is to try flashing your MOBO Bios to see if it helps! It hasn't happened since I've done this. I have an ASUS Prime. This is also my second 3090, the first was RMA'd after die for likey a voltage issue.
 
Update II: After the wonderful wattage efficiency update after the motherboard bios update, the issue eventually happened again. But, yet again it was during Apex Legends. So I uninstalled the game and tried Overwatch, Valorent, and Halo multiplayer, which seems to push the card the most. These games never caused the crash.
I continued to do some research and ended up realizing that with my new RMA'd card I never installed Precision X and only used MSI Afterburner. Two of the troubleshooting recommendations I saw was to update the Vbios of the card (which is done through Precision X) and to run DDU to completely uninstall any previous Nvidia and AMD drivers. I used an AMD while I waited for my RAM. So I removed the current and old drivers and re-installed the newest drivers again. Then eventually got the VBios to update. 
I re-installed Apex, and two weeks later the crash has not happened again while playing Apex. This is the longest it has been between crashes with the new card. So, I'm hoping this means I'm good!
 
-update Motherboard Bios
-clean any old video card drivers
-update Vbios
-Lastly, (optional) watch a couple of videos on how to optimize settings with the Nvidia control panel (primarily for the performance settings), this really seemed to help with lowering temps, especially in the loading/ queue screens.
 
Updated III: Close to a month later and still now crashing!
 
Good Luck