I'm having a problem connecting to a minecraft server?

My friend has a server which a few of us go on to build etc. But for some reason i can no longer connect but the other can. When i connect to it, no land renders just the sky, and after about 10 secs i'm disconnected a message appears saying "connection time out"

That means your internet is bad. It happeneds when i try to play minecraft using my phones 3g.
or the other way around, your friend has bad internet.
if you want a legit server with no lag, find a host. Those never have problems.

That is due to bad connection. Either you or your friends connection. As others can join then I'd say it is your connection. Sometimes a restart of your router will fix the problem, if not then you need to get a better router or internet package. If it is your friends connection who is hosting the server, then you either need to get someone with better internet to host it or use a hosting company which is what I do. They're very cheap and they run 24/7 unless you stop it.