Azure AD Connect Servcie will not Start

Question

I have installed Azure AD Connect. It has been running on our domain for over a month. The last couple days I am getting an email stating that "Your Identity synchronization from on-premises is unhealthy"
After some research I see that the service is not running and will not start. I used the default user account that is created when the Azure AD Connect is installed. NTAdmin\AzureAD or something like that.
I set the login to our domain admin account because it is in the permission group as an Azure AD Admin on the local server and I know this password. This didn't help.
how do I get this service started?
Thank you for you help in advance.

Answer 1

@Luke Skywalker if you have changed the logon account for Ad Connect service, you need to follow the additional steps documented at https://learn.microsoft.com/en-us/azure/active-directory/hybrid/how-to-connect-sync-change-serviceacct-pass. if after following the steps, the service fails to start, please look at the application and system event logs for any failures related to sync service.