Download Android Nougat 7.1.2 firmware for Magicsee C300 TV Box from here, here or here. Download previous firmware from here. Download Android Marshmallow 6.0 firmware for Magicsee C300 TV Box from here. Download Amlogic USB Burning Tool v2.0.8 from here or download Amlogic Burn_Card_Maker v2.0.2 from here.
Archive name: C300_S905D_android_7.1_20180309_upgrade_package
Archive file size: 791 MB
Model: Magicsee C300 TV Box
Platform: AMLogic S905D
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.