Download Android 6.0 stock firmware for CSA93 2GB + 16GB TV Box from here or here. Download Android 6.0 stock firmware for CSA93 3GB + 32GB TV Box from here or here. Download previous version from here.
Archive: aml_s912_q9377-CSA93Q2(2+16_kodi17.0)-20170206_mac / aml_s912_q9377-CSA93Q3(3+32_kodi17.0)-20170206_mac
Model: CSA93 TV Box 3GB RAM + 16GB ROM
Image file size: 712 MB / 712 MB
Platform: Amlogic S912
Image name: aml_s912_q9377-CSA93Q2(2+16_kodi17.0)-20170206_mac.img / aml_s912_q9377-CSA93Q3(3+32_kodi17.0)-20170206_mac.img
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.