Connect the USB cable to the PC while still holding the button.
Check the "Rockchip" sections of FreakTab or XDA Developers . Users often post "dumped" versions of the original factory firmware.
file for your device, the standard procedure involves using the RK Batch Tool Install Drivers: Ensure the Rockchip USB drivers are installed on your PC. Open RK Batch Tool: Run the executable and select your firmware file. Enter Flash Mode: Disconnect power from the TV box. Reset button (usually hidden inside the AV port).
You cannot flash this via the normal "Update & Backup" app. You need a PC, a USB male-to-male cable, and a tool called or AndroidTool (RKDevTool) .