Maybe someone has the firmware to upgrade, but always failure. That is because you have’t formated your TF card fully.
Today i will tell you how to make the start card, and then use it upgrade your tablet.
Password is geekbuing.com
2, Prepare a TF card to connect the computer.
3, Double click “winimage.exe” to install the tool.
4, The “being written to disk” is completed, then the TF card formatted once again, you can copy the extract files inside the TF card.