Hi AShabon,
Welcome to Microsoft Community.
I'm sorry to hear that you're experiencing issues with your Surface Duo. If the lower hinge is broken and the device is not powering on, it's possible that there may be internal damage that needs to be repaired.
Unfortunately, because this model has been discontinued, out of warranty support and service for such models is no longer available. We appreciate your commitment to Surface and apologize for any inconvenience.
Therefore, it is recommended that you try to go to a local third-party repair service to try to get help. Your SincerelyHahn. W - MSFT | Microsoft Community Support Specialist