If you don’t hear any strange beeps, odds are that the backlight has gone out. At 4 years, it’s a tossup on whether it’s worth fixing. Entry level model with an AMD processor? Pull the hard drive and toss it. You can get a HDD cable or enclosure to get your documents off. Otherwise, If you can find a compatible display, it’s just a ribbon cable and snapping the front panel apart, presuming you’re mechanically inclined.
You could also try an indie repair guy, somebody who works out of his house or a storefront, not one of the big places like Best Buy/Geek $quad.