In warranty you call it in.
Out of warranty there are no user serviceable parts. If you were to tackle self repair https://www.google.com/search?q=UN65KU630FXZA seems to offer a component above them all. You can guess that or go get a service manual and follow it's instructrions.
Aloha guys, I am new to this and am trying to figure out my t.v.
I have a samsung tv model un65ku630dfxza. it works fine for about an hour give or take, then we get all the colored lines and it shuts down and then boots back up. Once it shuts down it will continue to shut down and reboot. Any help would be greatly appreciated. Thank you in advance.