so i tried to overclock my lenovos y720 screen to higer refresh rate first tried 75hz the screen turn black and with lines okay restarted pc(back to 60hz) tried 63 hz and then was somehting silimar but saw some compressed screen, im just wondering is this some softare bug or i just cant overclock it, in the video tutorial i followed many did overclokc to hight hz their laptops but i cannot do it on mine, i want to hear your opinion