You must download every single part before you can extract the firmware. If you are missing part04.rar , the extraction will fail, and you won't get the .bin or .img file needed for the TV. Step-by-Step: How to Install the Firmware
Many users report that doing a "wipe data/factory reset" in the Android recovery menu causes the image to disappear. Firmware flashing is often the only way to restore the image.
Press and on the TV cabinet (not the remote). While holding the button, plug the TV back in.
Large firmware files (often over 1GB) are frequently split into multiple volumes—like part01.rar through part04.rar —to make them easier to upload to file-sharing services or forums.
Release the button once the screen displays an "Upgrading" progress bar.
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