G912 not updating

executor.xxx

Hello,

I have S/N912GSHG20136 and I want to update firmware to GT1_708N0_LTM8830.

I was trying to do it by SD card exactly based on the videos but nothing happened.

Then I am trying it through USB cable again exactly based on vides and after connecting cable again nothing happening.

I have burning tool 2.1.2

Thank you in advance for help.