A primary source for this specific firmware is KenotronTV , though it often requires registration or a paid subscription to download.
Typically installed via USB by placing the extracted .bin file on a FAT32 formatted drive and holding the power button while plugging the TV in. Download LDD H510 B138 3840x2160 768M Magic55 part03 rar
This specific file is a firmware update part for the , which uses the LDD.H510.B138 main board and supports a 4K (3840x2160) resolution. Key Specifications Device Model: Magic 55H5500 Main Board: LDD.H510.B138 Resolution: 3840 x 2160 (4K UHD) A primary source for this specific firmware is