Black screen after login

I am not able to by-pass black screen after login on Dell latitude laptop with mint 18 installed. Previous suggestions was to boot in single mode from GRUB menu. Booted in single mode, but not able to pass root password cause cannot type my user pw. So. Consequently not able to run var/Xorg/ to post. I am a newbie. So if responding on the treat plz consider to give detailed tip/answer. I am without laptop already 7 days since someone just responded load your bar/Xorg files. That wasn't helpful. Can post the screen of the single mode if help.