After I choose update firmware, I can see the warning do not power off. Later, the green led powers off. I wait more than 20 minutes but the screen remained blank all the time. After this, I power on the unit and It started with the old version.

Update firmware issue: Looking at the symptoms it looks like the downloaded firmware file is not downloaded correctly. It can be an issue from our server or internet connectivity while downloading the file. We request you to download the firmware again and try updating again.