Screen goes black
So, if it is a failing video card, it is going to start to fail when it is hot.
That's why turning up the fan and turning down the screen help, doing so keeps your machine cooler.
Your typical Apple store is kept at meat locker temps with all those machines running. Meaning they might not be able to reproduce the problem. Take a video of it failing at home on your phone and take that with you. It's not like you're going to make this stuff up! but hard evidence might be necessary to get them to replace the video card.
PS you can hit alt+command+eject and then space and the screen will come back. Don't need to hard reboot.
So, if it is a failing video card, it is going to start to fail when it is hot.
That's why turning up the fan and turning down the screen help, doing so keeps your machine cooler.
Your typical Apple store is kept at meat locker temps with all those machines running. Meaning they might not be able to reproduce the problem. Take a video of it failing at home on your phone and take that with you. It's not like you're going to make this stuff up! but hard evidence might be necessary to get them to replace the video card.
PS you can hit alt+command+eject and then space and the screen will come back. Don't need to hard reboot.