Download Android 7.1 stock firmware PC version for Mecool M8S PRO W TV Box from here, here or here. Download Android 7.1 stock firmware SD card version for Mecool M8S PRO W TV Box from here, here or here. Download Amlogic USB Burning Tool v2.0.8 from here or download Amlogic Burn_Card_Maker v2.0.2 from here.
Archive: M8S PRO W-NHG47L-20171030.152444.V0619 / M8S PRO W-ota-20171030.152444.V0619
Model: Mecool M8S PRO W TV Box
Image file size: 810 MB / 882 MB
Platform: Amlogic S905W
Image: M8S PRO W-NHG47L-20171030.152444.V0619.img / M8S PRO W-ota-20171030.152444.V0619.zip
Build number: Amlogic/p21x/p21x:7.1.1/NHG47L/20171030.152444.V0619:userdebug
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.