Samsung smart tv gets restart on its own and continuously and this is due to firmware software update, the easy fix will be to perform factory reset your Samsung smart tv, fix this follow below steps.
Samsung smart tv restarting on its own Reboot continuously

Step 1: Power off the tv and wait for 5 seconds
Step 2: Now on your remote press this key combination to enter into service menu.
Step 3: Grab your remote and press this Key combination: Press info button then menu and mute button and power button to enter in to service menu.
Step 4: Once you enter service menu, click on options.
Step 5: Now click ok on Factory reset
Step 6: Now your Samsung smart tv will be turned on and will be restarting on its own.
Note: wait for few seconds until your Samsung smart tv turns on.
Step 7: Once Samsung smart tv gets turned on, Click on setup and setup your smart tv and follow your onscreen instruction on your smart tv.
That’s it once you have setup your smart tv after performing factory reset then your Samsung smart tv restarting on its own or rebooting issue will be fixed and your smart tv will not turn off and on again.
Factory resetting Samsung smart tv is easy fix to get rid of restarting your Samsung smart tv on its own which is a rebooting issue. If you still face problem then call Samsung customer care support.
Update Software to fix Samsung Smart tv Restarting on its own continuously:
Sometimes this may be due to glitch as well so go ahead and update your Samsung smart tv.
Press menu->Support->Software Update and update Samsung smart tv.
Why Samsung Smart tv Restarting on its own?
This causes due to the firmware software update issue or motherboard issue, software needs to be updated and when you factory reset your Samsung tv it gets updated.
Update your samsung smart tv and do a factory reset to fix if you face samsung tv restarting on its own.