they probably have bad computers
it means the server has gone down such as minecraft server has crashed or the server owner has lost Internet connection
either you don't have An internet connection or you have a cracked account on minecraft and it wont let you on. The alternative to this is their minecraft server was having issues.
If you are the host of the Server, you open up Minecraft Server . Wait for it to load then it will say its ready. If you are going to someone else's server, and it has no bars, then there server is not active. (Which means they dont have Minecraft Server up).
type on google minecraft.net server and download the server jar.
You can have zero bars and still be on a server.
No I can host one fine with a wireless connection
this may be because you have bad connection the the host of the server or you have no internet connection if this is only happening with 1 server it is your connection or you have the ip wrong
Connection Refused: Connect probably means there is no server running on that ip address.
that happens you probably got banned or kicked off the server
It means the server is iether down,reloading or the server creator hasn't port forwarded the server It means that the set timeout time in the java code of minecraft is less time than it took to connect to the server meaning the connection has 'timed out' this is because the server has been unresponsive for more then said amount of time.
If the message "Connection refused:connect" appears when joining a server, it most likely means either the server is not currently online, or your internet is down.
It means that, as you are trying to connect to a server, the server is not responding, after a minuet or so it will show this message. This could mean the server is offline or that your connection to the internet is poor. (Or the server host's connection to the internet is poor.