Download MK902 Android Jelly Bean 4.2.2 stock firmware from here.
1. Download the firmware archive and extract it on the desktop.
2. Second, connect MK902 to your computer. Prepare a USB cable (male USB to male USB cable); insert one USB port to computer USB host. Prepare also a thin metal stick; press the recover button like in the image below. Don’t lose the stick, at the same time, insert another USB port to the unit USB slave port. After 3-5 seconds, lose the stick.
3. Install driver using RK Driver Assistant.
4. Burn the image with Rockchip Batch Tool v1.7 using ‘Restore’ button.
This process will take about 3 minutes, please wait patiently, during recovery/upgrade, don’t remove the USB cable and don’t power off during updating or recovering. FThe first reboot of the unit after recovery/update will take more long time than usual, and even occur some lag issue, it’s normal since internal apk files need to be decompressed and occupy RAM, after 5 minutes, then the system will be running well. So don’t worry about that.