UserAgent: Mozilla/5.0 (X11; CrOS x86_64 8743.76.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.79 Safari/537.36
Platform: 8743.76.0 (Official Build) stable-channel edgar

Steps to reproduce the problem:
1. Recurring problem, but unable to reproduce
2. 
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What is the expected behavior?

What went wrong?
Several times now, usually while keyboarding, the screen will go black. Usually, this blackout lasts only a moment or two or goes away when I touch the trackpad or any key on the keyboard. Once, however, it didn't fix itself until I closed the lid of my Acer Chromebook 14 and reopened it. I first noticed the problem a couple of weeks ago, when I was experimenting with the beta channel, but it has persisted since I returned to the stable channel. 

Did this work before? Yes 

Chrome version: 54.0.2840.79  Channel: stable
OS Version: 8743.76.0
Flash Version: Shockwave Flash 23.0 r0