The screen is lit up (dark blue or grey) but no picture or menu is displayed.
The device starts, then immediately restarts before the home screen appears.
Most firmware for this board is flashed to the eMMC (embedded MultiMediaCard) memory chip. How to Update 40-MT56S1-MAE2LG Firmware
If you have obtained the correct .pkg or .bin file for your specific panel and board, follow these steps to perform a USB update: