Hello Ibinema,
Here are a few things which you can do:
1. Please check if you are able to ping the CVM.
2. Check if it is maintenance.
3. Open/Launch the console and check the status of the CVM. 
4. If you are able to ping and launch the console. Check the status using this command “cs | grep -v UP”
We need to know the reason why CVM doesn’t start.
5. Check if you see any error in the NCC health check related to any other hardware.
6. When HDD was replaced, was it added back to the cluster?

Few documents:
1. sample HDD replacement on Nutanix hardware:
https://portal.nutanix.com/page/documents/details?targetId=Drive-Replacement-Platform-G7:Drive-Replacement-Platform-G7
2. portal.nutanix.com/kb/4639

Regards,
Chaitrali