Hello! I OSMO updated to Firmware v1.6.2.10, firmware is successfully established. But after installing the new firmware has ceased to show the screen on your phone (it's black), all other functions are working properly. On the SD card takes video normally. What should I do? And you can bring back the old firmware? Thank you!

This is happen to me of late. I simply ejected the sd card and  put it back in and it rectified the problem.
Give it a try

Sd card is taken out and put back formatted, but it did not help. Program DJI GO reinstall the same does not help.

Hello.
What's the model of your phone? If you have other phones, please check if you can connect to the DJI GO App normally.
You can try to upgrade the firmware v1.6.2.10 via the SD card again. If you've installed the latest firmware version, you can't roll back to the older one presently.

Wait for your response.
Thanks.

Hello! I have a model of the smartphone Lenovo s860. I've updated via the SD card. Nothing changed.

When did you buy the Osmo? If you bought it recently, you can contact the seller and see if they can do a replacement for you. Otherwise, you can always contact support@dji.com and we're glad to help you repair it. Thank you.