so, i bought this laptop(ROG strix) few days ago only and when i let it for some time the screen turns off and when i press any key on the keyboard, it turns a little bit grey but never fully on but the keyboard lights turns on. And only after i press the power button for long period of time, it shuts down and when pressed power button again, it turns on from begining. what is the problem here?
It sounds like you get the grey screen when coming out of sleep mode.
Here is a video that might fix the grey screen.
When your laptop comes out of sleep with a black screen, try pressing Ctrl + Shift + Win + B
This should restart the graphics driver.
One thing that would fix it would be to disable sleep and hibernate, your laptop will no longer go to sleep.