Continue holding the power button until the screen shows an "Upgrading" or "Software Updating" progress bar.
Press and hold the button on the TV (not the remote) and plug the TV back in. Download 40b7500 715g6686 moa 001 004k BIN
: Copy the 40b7500_715g6686_moa_001_004k.bin file directly to the root of the USB drive. Do not put it in a folder. Installation : Unplug the TV from the power outlet. Insert the USB drive into the TV's USB port. Continue holding the power button until the screen
Finding and installing the correct firmware is crucial for reviving a TV that is stuck on a logo or experiencing boot loops. How to Use the Firmware File Do not put it in a folder
What happens if a firmware update fails? If a firmware update fails, your device may become unresponsive or stop working entirely. Best Practices for Applying Firmware Updates - Quadbridge
: Ensure your USB drive is formatted to FAT32. Lenovo and other manufacturers warn that using the wrong format or an interrupted update can "brick" the device.