3840 x 2160 (4K UHD) at a 60Hz refresh rate (Ref60). Chipset: HiSilicon HI3751V553. Operating System: Android 7.0. Memory: 1GB DDR3 RAM and 8GB ROM.
Features built-in Wi-Fi and an RJ45 Ethernet connector. How to Use the Downloaded Firmware Download HV553 PC821 3840x2160 Ref60 part05 rar
The standby light should begin blinking, indicating the software update is in progress. 3840 x 2160 (4K UHD) at a 60Hz refresh rate (Ref60)
Copy the extracted software file (often named allupgrade_...pkg or similar) to the root directory of a FAT32-formatted USB drive. Installation: Download HV553 PC821 3840x2160 Ref60 part05 rar
Because the file is labeled "part05," you must download of the archive (e.g., part01 through part05) into the same folder before you can successfully extract the firmware file.
Press and hold the button on the TV keypad and then turn on the main power.