Issue with SCOM database connection after move

Hi,
We have had to move our operationsmanager and operationsmanagerDW and are now having connection problems. The DBs were on a cluster but now on a single server. All management servers are showing as healthy in the SCOM console so the operationsmanager DB itself must be working but I can’t reset alerts.
The DB server now seems to be rejecting connections to the DW but alerts are still being logged.
This shows in the logs on the management servers every 10 minutes. Have tried turning off the firewalls to eliminate them:
OpsMgr Management Configuration Service failed to execute bootstrap work item ‘ConfigurationDataProviderInitializeWorkItem’ due to the following exception
System.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - The remote computer refused the network connection.) —> System.ComponentModel.Win32Exception (0x80004005): The remote computer refused the network connection

There is also this warning every 5 minutes:
The Root connector received an exception from the Config Service on StateSyncRequest:
System.Runtime.Remoting.RemotingException: Failed to connect to an IPC Port: The system cannot find the file specified.
Can anyone help with this please?
Cheers,
Ian.