Flashing the wrong firmware can permanently brick your television. Always verify that your Mainboard Model (MS3458-U801) and Panel Number match the file exactly before proceeding.
MS3458_U801_3840x2160_Cobia_CLEDTV5517UHD.rar Resolution: 3840 x 2160 (4K UHD) Mainboard: MS3458-U801 Description
Press and hold the on the TV panel (not the remote). While holding the button, plug the power cord back in.