stays black when you turn it on

K SEARS could be caused by a bad backlight, bad LCD panel or bad GPU. First thing you want to do is to attach an external monitor. If you have a proper image with that you know that your GPU is ok (motherboard). Then focus on your LCD. Check with a flashlight by shining it at an angle against your LCD see if you can make something out. That would be a failed backlight possibly caused by a bad inverter. Check on here how to fix it. You can also download the service manual from here which will show you the inverter as well as LCD replacement procedure.