Make sure you have a valid username/password pair on the device.
username "johndoe" password "itsasecret"
line telnet 0 4 shutdown line ssh 0 4 no shutdown
You can and probably should apply an access-list to limit SSH to your management subnet else the Internet will try to brute-force your SSH login. They probably won't succeed with an uncommon username and a good password but it can gobble CPU.
ip access-list standard admin-access permit 192.168.200.0 0.0.0.255