Changing service account password breaks Azure AD Password sync

Solution 1:

To add to the mix, we don't know the Azure AD Sync Service account password, so we can't get into the connector app.

I don't understand what you mean. You don't need to know the service account password to launch the Azure AD Connect Synchronization Service console. Try this:

On your Azure AD Connect server launch the Azure AD Connect Synchronization Service console.

Switch to the Connectors tab.

Select the local Active Directory Domain Services connector.

Click Properties in the Action pane.

Select the “Connect to Active Directory Forest” setting.

Enter the new password into the password field and click OK.

Open an elevated Powershell prompt and type the command “Import-Module ADSync” and press enter.

Type “Start-ADSyncSyncCycle -PolicyType Delta” and press enter.

In the Azure AD Connect Synchronization Service console switch to the Operations tab and watch the sync cycle. If it's successful, you'll see it. If not, you'll see why.