Download latest KitKat 4.4.2 stock firmware for CX-S806 TV Box from here or here. To flash firmware on this box from PC via AMLogic USB Burning Tool read this article.
Archive: S806_S812_DDR2G_WIFI6210_camera_sdk0823_141008
Model: CX-S806 TV Box
Image file size: 480 MB
Platform: Amlogic S812
Update file: S806_S812_DDR2G_WIFI6210_camera_sdk0823_141008.img
Update file: S806_S812_DDR2G_WIFI6210_camera_sdk0823_141008.img
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