Please follow the instructions below to troubleshoot the TV...
Step 1: Unplug the TV cord from the power socket
Step 2: Leave it unplugged and while it's unplugged press and hold the Power button on the TV for 25 seconds
Step 3: Release the power button and plug the cord back in. Turn ON the TV using the remote control or manually and check if the lines are still visible
Note: IF the issue persists then please contact our Customer Support Team at 888-842-3577