ASUS has released a new firmware for its Transformer Pad TF300T tablet, namely the 10.6.1.15.3 package version, that brings improvements to the device’s overall performance.The developers managed to resolve the IME bug and other minor issues. When taken alone, these fixes don’t improve performance that much, but together they really make a change.
Moreover, HDMI compatibility with other devices is improved, Gmail works better with Splashtop, and the security level is raised because now only the owner’s account is able to access any settings or UI referring to the external storage.
Bear in mind that the firmware update process isn’t able to do SKU conversion or downgrade version, and also that installing the wrong SKU may result in update crashes, and therefore device malfunction.
So, in order to find out what SKU you are using, go to Settings → About Tablet → Build Number, and there you should be able to read the SKU that consists of the first two or three letters of the build number (namely the letters before the underscore line).
Now that you have taken into account all the important aspects, follow the link below, and from the list download the file that is compatible with your device.
ASUS Transformer Pad TF300T Firmware 10.6.1.15.3