Hello,
I would like you to provide more details about your device. Before attempting a firmware update, what was the device configuration? Have you made any mobile configuration changes, was remote access enabled, anything else other than default settings?
Could you connect to the device via command line or SSH and post the output of the following command:
Another thing you could do is to execute the command troubleshoot.sh in the command line. This would generate a log file in your device located in /tmp directory called similarly to troubleshoot.tar.gz. I would like you to copy this file using WinSCP to your PC (follow instructions provided here) and attach that file by editing your question.
Best regards,