Download Android Pie 9.0 stock firmware for Qintaix Q9S Pro TV Box from here or here. Download previous firmware from here. Download Android Oreo 8.1 firmware from here. Download Amlogic USB Burning Tool v2.1.6 from here or download Amlogic Burn_Card_Maker v2.0.2 from here.
Archive name: aml_s905x2_9.0_Q9S_PRO_mac_wifi_20200306
Archive file size: 641 MB
Model: Qintaix Q9S Pro TV Box
Platform: AMLogic S905x2
System: Android verson 9.0
Build number: franklin-user 9 PPR1.180610.011 20200306 test-keys
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.