Thanks for the error messages. Can you check these three things:
1. Make sure SQL Browser service is running on the server.
2. If firewall is enabled on the server, you need to put sqlbrowser.exe and/or UDP port 1434 into exception. Before I mentioned 1433 but check on 1434 too.
3. You said you can ping the server, but can you resolve the DNS of the manager server from the potential collector server?
Try these one at a time and see if it fixes it. Let us know.