Download Tecno S1 official stock firmware from the link here, and follow the provided flashing instructions to learn how to flash the stock rom.
If you notice that any of the links provided below is broken or doesn’t work, please post in comments section so we fix and update it ASAP.
File Name: Tecno s1 MT6580.rar
Size: 700 MB
Firmware – Download
How to flash
After downloading the firmware, follow the instructions here to flash.
Flash with SP Flashtool, and if you have any questions or complaints do not hesitate to post in comments section below for assistance. Use the password indicated above to unlock archive.