Dell Precision 7820 Tower stopped loading after updating BIOS by update "7X20T_2.35.0.exe"

I have Dell Precision 7820 Tower <Private data removed from public view. DELL-Admin>. In january this year I decided update BIOS on my computer. So I dowloaded the updatefile from oficial site DELL and installed it from under  Windows10. The instalation finished itself saccessfuly and computer rebooted itself. But to my greatest surprise and disappointment, my computer no longer boots. When it is turned on, there are no messages on the monitor screen other than the message from the monitor itself that the video signal from the computer is not send to the monitor. Therefore the monitor simply goes to sleep. There is no response to keys presses on the keyboard. Does anyone have similar experience and how to fix it? Help me please. I would be grateful for any useful practical advices.