So happy I found this thread. I purchased a EVGA GTX 1080 FTW off Amazon on 2 September, arrived two days later and all seemed well. Installed it in my existing rig. Played Kerbal Space Program, Arma 3, Sleeping Dogs, Project Highrise, Homeworld Remastered, Overwatch, and Starcraft 2 without issue. Also ran 3Dmark, Furmark and Heaven benchmark software with no problems. I did not touch the clock settings.
I first recall the black screen/100% fans issue happening while playing Paragon. I remember it happening 2 or 3 times after seeming random amounts of time, being annoyed and having to manually reset my PC but I stopped playing Paragon and didn't encounter the issue again until a week or so later when I started playing Mad Max. The 100% BS happened every time I played Mad Max after random amounts of time, sometimes within a few minutes, sometimes after a couple hours. I started to realize there was a problem. I ran Furmark for several hours, started running temp monitoring software, cleaned out my case, cleaned my CPU heatsink (temp software showed CPU running hot and I found a thick layer of dust on the heatsink). Swapped out PCI-E cables and removed unneded ones (used to have SLI in this case). Reseated the GPU and installed sturdier retaining screws instead of the case-provided plastic snappy thing. Reinstalled drivers and did all the other normal troubleshooting stuff. The issue persisted in Mad Max.
Then I added a custom fan profile in Precision to keep the GPU temps below 65 C (stock settings had it pushing 80+ C in Furmark). The issue seemed to stop in Mad Max and I played for a couple weeks without any issues so long as the custom fan profile was activated. If I deactivated the fan profile, it returned immediately. At this point, I was considering RMA but I saw reports that the GTX 1080 stock fan speeds were insufficient so I figured that was the problem and this fan profile would be the end of it.
A couple days ago, I tried to play Rome 2 Total War. The 100% BS happened within one minute of entering the campaign map every single time. I went looking for more answers and found this thread. I'm not sure if this game is more likely to trigger the issue or if as others have said the issue tends to get worse over time.
Luckily, I was still within the 30 day window with Amazon so I ordered a replacement from them (yay Prime free one-day shipping). Unfortunately, they said they would be delaying the order until October 4th but the next day they updated and said they would be delivered by Thursday. I was happy to find that Amazon does free cross-shipping on returns and you just have to return the old item within 30 days to avoid getting charged. I didn't realize EVGA was doing free Advanced RMAs for this issue until after I ordered the replacement. The cross-shipping with collateral option was unacceptable to me, I didn't want to pay extra for Advanced RMA privileges, and I didn't want to be missing a GPU for X number of weeks. If the replacement card I get from Amazon has the issue as well, I will attempt to get a free Advanced RMA from EVGA to ensure the next card has whatever fix they seemed to have found.
I'm really curious to know what issue EVGA found with the cards. It seems very strange that only certain games, even ones that are not as demanding as others, seem to trigger the issue. That being said, I feel they are handling the issue well. I've bought EVGA since the GTX 400 series and their handling of this has retained me as a customer, despite the inconvenience.
Edit: Forgot to say that Debug Mode in the Nvidia Control Panel or downclocking the GPU 100 Mhz or so seemed to make the issue go away for me in Rome 2 Total War. I haven't had any issues since I enabled Debug Mode and will continue to use it till the replacement arrives.