Hi,

have you kept the firewall settings in mind. Have you allowed the remote powershell ports?

http://blogs.technet.com/b/christwe/archive/2012/06/20/what-port-does-powershell-remoting-use.aspx

Another possibility to check the running server:

You can use the Registered Servers feature of the SSMS. Generate a serverlist to import and start a new query. All server without connection would be listed in the messages window.