Download Android Lollipop 5.1.1 stock firmware for MK903V TV Stick from here or here. Download Android KitKat 4.4.2 stock firmware for MK903V TV Stick from here. Download a previous firmware version from here.
Firmware file name: update.img
Model： MK903V TV Stick
Image file size: 312 MB
Platform: Rockchip RK3288 / RK32
Boot version: 2.19
FW version: 5.0.00
Build number: rk3288_box-userdebug 5.1.1 LMY47V eng.root.20170524.224000 test-keys
Model number: rk3288_box
Caution:Please do not update firmware unless you know what you are doing, you really want it or it is absolutely necessary. Firmware updates may occasionally have bad results, like bricking your device, temporarily or permanently. The firmware update process is done entirely at your own risk. Before attempting to update the firmware, back up your data.