okay do this only power one board not all three. And make sure you filled in three pools not one or two pools.
i only had 1-2 pools so i went ahead and added a third; I'm going to reboot and wait 1-2 hours and check back. (trying first with 3 boards)
The miner needs time to do its auto-tuning, that can be anywhere from several minutes and by some reports up to an hour. During tuning you get the "Connection refused" message and it goes away when tuning is done.
How long are you waiting?
Any whitespace at the end of your pool and/or user info? If so delete the space because it makes those entries invalid.
Usually I'll wait an hour. I filled in the third pools info because I only had two and will touch back in an hour or two with results.