Same probleme here... Have you fix it ?

I had the same problem, used my new R11 only 1 month, and yesterday it did not turn on at all. Send it to the service, probably a problem with the motherboard. must wait 6 weeks for a new parts. Very disappointing, I chose Alienware for reliability. 

Same problem here...

==================

What shows in Windows Reliability Report ?

Same problem here. Brand new R11 with RTX 3090. Will randomly go to the black screen. When I unplug and plug in the DP cable screen comes back but the computer is frozen with digital artifacts on the screen.  Was with Dell support yesterday for hours and it was determined that it was because I was using HDMI instead of DP on the Dell  49" Curved Monitor - U4919DW.  Obviously not the case as the black screen has happened twice today already and required a hard power reset both times. Reading other forums and seeing a lot of people with this problem. 

System:

Latest Windows 10 Pro
Latest Bios 1.0.3
All Alienware updates and latest game-ready Nvidia drivers for the RTX 3090

Did you disable all non-MS services?  I did (but re-enabled Steam and other game clients along with the nVidia service) and the PC stopped doing the black screen thing.

I'm using the R11 mainly for architectural design and rendering and don't have any games installed. What services would you suggest turning off?

You have to turn them all off and then start adding them one at a time to isolate what the problem could be.  I haven't yet completed this step beyond Steam and nVidia and a few other gaming clients.  It's a boring process because it takes a bit of time to add one and then use PC during that window to see if crash recurs.  Start by disabling all non-MS services in MSCONFIG.

Gotcha! Thanks. So just look for non-Microsoft services and disable and see if it still happens. 

What I am noticing is that it appears to happen mostly if I go to a website that has some kind of motion graphics.  As the website loads and I see the graphics start - BAM! - black screen. I unplug the DP cable and plug it back in and I see a static screen (with a few digital artifacts) but the computer is completely frozen and I have to do a hard reset.

I am seeing a lot of people on different forums having this problem with the 3000 series RTX cards.  I have reached out to Nvidia support as well as Dell support to see if this can get escalated and a new driver issued.  I believe it is a driver problem more than hardware considering the amount of people having this issue.

Of course - every time you start a support ticket you have to go through all the dumb stuff again. I will not be doing a clean install of Windows as this is a clean install on a brand new computer!!

Good luck.  For me it seemed to be some service.  Go to MSCONFIG, then click the services tab, then tick the "hide all MS services box" then press the disable all button and then restart PC.  You might have luck if it was same issue as me.

I seem to recall that web-browsing issues such as this was due to the browser using hardware acceleration.

What is Hardware Acceleration and How to Enable in Browsers? » WebNots