Download latest Android 7.1 stock firmware for H96 Pro Mini TV Dongle from here or here. Download previous firmware from here. Download Amlogic USB Burning Tool v2.0.8 from here or download Amlogic Burn_Card_Maker v2.0.2 from here.
Archive: H96Pro Mini Firmware+Guide+Tools
Model: H96 Pro Mini TV Dongle
Image file size: 737 MB
Platform: Amlogic S912
Image name: aml_7.1_s912_q8723bs_H96PROmini_KDMC_mac-20170731.img
Inside archive: firmware + Amlogic S912 burnning tool (setup_v188.8.131.52_build7) + Guidance.pdf
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.