Enter the bios, if it shows there its probably a faulty screen/gpu (gpu itself or vram, vrm etc). If not try completely uninstalling your nvidia/intel graphics drivers and if its gone after that i was a software problem.

Please in the future try being more especific with your asus model number and operating system, and describe better your problem. We CAN'T possibly give a correct answer or solution unless you give us more information.

(really hope yours is just a software problem, cheers!)