Scramble channel can mean two things;
1.)The account is disconnected.
2.) The signal level is low and dish might need realignment.
If your account is up to date, then follow the following steps to check your signal level;
1. Press menu from remote.
2. Browse to the right until you come to settings.
3. Select channel search from the settings menu.
4. Check the Quality percentage of the signal. 0% means that dish needs to be realigned again.