svim
Extreme Android User
At this point if your phone isn't even working you might want to start over by re-flashing a stock ROM so it's functional again, then try to root it again. As you mentioned initially playing around with Kingroot I'd be wary it didn't just screw things up to begin with.Still need guidance!
Reliable Samsung stock ROM sources
sammobile
https://www.sammobile.com/firmwares/galaxy-s7/SM-G930V/
updato
http://updato.com/firmware-archive-select-model?q=sm-g930v&exact=1
These links are for a less involved root method. Each basically lays out the same process using Odin (note that none involve Kingroot in any way):
https://androidmtk.com/root-samsung-galaxy-s7-sm-g930v
https://www.skyneel.com/root-samsung-galaxy-s7-sm-g930v
https://geekaxe.com/root-samsung-galaxy-s7-sm-g930v/