How to troubleshoot a Smart TV that is stuck on the loading screen?

Check the power source:
Check to make sure that the power cable to the TV is properly plugged in and providing power.
Check for other connections:
Confirm that any other connections from the TV to additional devices, such as an external hard drive, are all properly connected.
Perform a soft reset:
Do a soft reset of the TV by holding down the power button for 10-15 seconds to see if that resolves the problem.
Perform a full reset:
If performing a soft reset did not resolve the issue, then do a full reset of the TV by unplugging it and leaving it unplugged for 1-2 hours before plugging it back in and testing again.