My Nitro 5 AN515-51 suddenly started turning itself off at random times. It would go black, and pressing a key would bring up the sign in screen. It would repeat this before I could even sign in. I sent it to Acer, who said there was nothing wrong with it. I tried various fixes I found here, but they didn't work. I was very frustrated.
Then I found the cause--my new FitBit Charge 2. We watched as the screen and keys went black each time the FitBit got close, then lit back up when it was pulled away. The laptop only shuts down if the FitBit is near it. It doesn't do it 100% of the time. Sometimes it will continue working when I'm wearing the FitBit. But once it shuts down, it won't stay up until I remove the FitBit.
The solution was simple--Don't wear the FitBit when I'm on the laptop. No problem any more. I am happy to be able to use the laptop again without wanting to throw it across the room. (Yes, I was that angry at it.) And I'm especially happy that it's such a simple fix.
I'm sharing this in hopes that 1) someone else will be helped by this same solution and 2) maybe Acer would consider trying to figure out why this is happening, and how to avoid it in future models.