Download Android Nougat 7.1 firmware for Z69 3GB RAM + 32GB TV Box 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 name: 2073257 Z69 TV Box ROM and Tool
Archive file size: 1.11 GB
Model: Z69 TV Box
Platform: AMLogic S905x
Inside archive: firmware + aml烧录工具及说明 (USB_Burning_Tool_v2.0.8_x86 & amlogic using guide.png)
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.