Firmware for this board is hosted on several technician-focused sites: Receiver Pro provides various 55-inch and 65-inch variants.
After extracting the parts, you will likely find a file named something like allupgrade_v553_8G_1G_60.bin . If the board doesn't recognize it, you may need to rename it to allupgrade_v553_sos.bin . Flashing: Turn off the TV and insert the USB. Download HV553 PC821 3840x2160 Ref60 part10 rar
Turn on the main power. The standby LED should begin flashing rapidly, indicating the update is in progress. Firmware for this board is hosted on several
Software Zone lists specific builds for brands like Telezone. Flashing: Turn off the TV and insert the USB
Do not turn off the power until the process reaches 100% or the LED stops blinking. Where to Find Files
You cannot use part10.rar alone. You must download all parts (e.g., part01 through part10) to successfully extract the final .bin firmware file.