Success recover my MyCloud 3TB with fast blue blinking light after update firmware!

There are directions both in English and Russian located at this link for how to unbrick a first gen single bay My Cloud.

https://fox-exe.ru/WDMyCloud/WDMyCloud-Gen1/

The files one generally uses for the gen1 unbrick can be found at this link:

https://fox-exe.ru/WDMyCloud/WDMyCloud-Gen1/Backups/