Download latest Android KitKat 4.4.2 stock firmware for Cubot S308 smartphone from here or from here. Download previous version from here. Download another Cubot firmware from here.
Archive name: CUBOT S308 new fw
Archive file size: 369 MB
Model: Cubot S308 smartphone
Platform: Mediatek MT6582
Upgrading notes (see this video tutorial)
1 – Download & unpack FlashTools. Run Flash_tool.exe
2 – Unpack Rom in folder
3 – Select MT6582_Android_scatter.txt in folder on rom. And wait.
4 – Check Option->USB Model, click USB Model
Choose Option->DA DownLoad All->Speed->High Speed, click High Speed
5 – Turn off your phone, remove the battery.
6 -"Press F9 (or hit Download button)"
7 – Connect your phone into the computer with USB data cable.
8 – The process will start and a red progress bar will appear after color purple, yellow.
9 – And green circles display.
10 – Boot your phone !
11 – Restart !
12 – Enjoy !