G3 stylus (d690n) dead after flash in Octopus.

We updated G3 stylus (D690n) that had crashes on android, the Octopus with a downloaded firmware support (D690_V10C_00.oct) and now not connecting device and is only recognized as "LGE AndroidNet USB Serial Port" when I connect device without battery and holding the volume button.
I would like to help.