Flashing the wrong firmware can "brick" the board or cause a distorted/upside-down image.
To download the firmware for the mainboard specifically matched for the LC390TU1A panel, you can use specialized technician repositories like Receiver Pro or Software Zone . Download VST59S PB801 LC390TU1A rar
Use a USB 2.0 drive (8GB or 16GB) formatted to FAT32 . Flashing the wrong firmware can "brick" the board