Hp laptop screen is black but lights still on.

My laptop stopped working a year ago my uncle gave me his laptop for christmas and when we tried powering it on the screen staed black. I tryed to do a bunch of methods and sometimes the screen would light up for a couple seconds and then turn black again! I don't know what to do. And its too expensive to get proffesional help. If you have any idea please let me know! (Caps lock is blinking)