Have you tried an external monitor hooked up to it? Hooking one up will help determine if it's a video problem, or a display problem, and also let you see if it is booting as well as long as the external monitor is selected for use. (May need to use keyboard function keys to turn it on.)
The screens are notorious for going out. But before you replace the lcd hook up a monitor to it. I have replaced a screen and it is pretty easy. A replacement can be had on ebay for a good price. But there is also the LCD inverter which are a lot cheaper than a screen. Also could be a backlight. I am told a way to test those is to shine a flashlight on the screen when you have it on. Though backlights are also cheaper than a whole new screen it will require removing the lcd and soldering new backlights on them.