Download Android KitKat 4.4 stock firmware for MK808B Mini TV from here or from here. Download previous Jelly Bean stock firmware from here.
Firmware: T005_T011_public_2tianxian_RTL_12_20140709_V4.4
Image file name: T005_T011_public_2tianxian_RTL_12_20140709_V4.4.img
Archive file size: 285 MB
Platform: Rockchip RK3066
Boot version: 2.13
FW version: 4.4.02