Congratulations! Your OnePlus 3T is alive again. But you are not done yet.
The phone will prompt you to update to Android 9 Pie. However, if you plan to root or install a custom ROM (which is the best part of owning a 3T), do this first: oneplus 3t unbrick tool
The Unbrick Tool will take a few minutes to complete the process. Be patient and do not interrupt the process. Congratulations
The OnePlus 3T has two major variants:
Using the wrong region tool can lock your bootloader to the wrong band configuration. Wait for the process to complete : This