I have 2 Apple TV's in my home. When I attempt to login, is say cannot connect to the internet. I have reset both Apple TV's and also restarted them both.but still cannot connect to the internet. I al reset my router and still not change

I have 2 Apple TV's in my home. One is 2nd Generation and the other is 3rd Generation. One one that is 2nd Gen cannot connect to the internet. First I restarted, the I rest it and I even changed the password. still no connection. So I purchased the 3rd Gen TV and I have to same problem, but they are in different rooms. Before I had no problem with my 2nd Gen TV, but then one day it did not connect. I even had my internet provider come and check my internet and it worked ok, but no connection with the Apple TV. I have tried everything but no results. Somebody please help me.

Regards,

Richard