On my wife's Dell 1525, while using Chrome the screen would just black while viewing Youtube videos or videos from Facebook. Now, the screen was the only thing lost, what was going on and sound and all were working, only the screen was black. I found on a Ubuntu site the answer. Go into the setting and then into the advanced settings, scroll down to the ( system ) and uncheck the ( use hardware acceleration when available ). This cured the screen going black while viewing videos, I don't know why, but this was an answer to our problem, maybe it will help you.