I have a problem with the screen of my acer aspire v5-591g laptop, when booting som times the screen is just black. External monitor works fine. If i restart the pc a couple times i will work fine. But then after having been on for x amount of time the screen will go grey, having blackline vertical and horizontal. But if i restart it by pressing the turn on/off Bottom for some seconds. It will work again. Im very confused about it and cant find the trigger, tilting the screen does nothing. And monitor works fine as well when it goes grey.