Sunvell T9 firmware is here and this will give you latest Android 8.1 operating system on it. It is for the version that comes with the Rockchip RK3288 quad core processor, Mali 450mp2 GPU, 4GB of DDR3 RAM and 32GB of flash storage. Also onboard are Wi-Fi b/g/n and Bluetooth 4.0 connections.
To install the firmware for the Sunvell T9 Android TV box, you will have to download the firmware from here.
Install rockchip drivers with administrative rights on your computer using Rockchip driver assistant. Now, fire up rockchip batch tool and click on … dots to browse for the firmware that we download earlier. Make sure you have the img file. If not, unarchive it.
Press reset button on your Sunvell T9 android TV box and while keeping it pressed, connect it to the computer. The green button should lit up. Select the restore option and start the update process.
Once the android firmware has flashed successfully, you will get the message that the restore was done successfully. Wait for the android TV to restart as it can take 5-10 minutes.