screen is black after I restarted it samsung note 3

hi, my note 3's screen is black although for some reason i can see the top part of it (where it shows the battery and wifi) and i can drag it down too. i can open s finder and check the gallery which thankfully did not have any lost images. the problem is i cant seem to open the main screen and i want to back up the files but when i close s finder, it turns black again. please help me. i need to recover my files but my usb thingy is not debugged.