If your picture is rolling and/or black and white, you've probably put your receiver in PAL mode.
Follow these steps to correct the problem:

1. Turn the power of the receiver off using the switch on the back.
2. Turn the power on.
3. Press the "Menu" key.
4. Press the left arrow key two times.
5. Press the down arrow key one time.
6. Press "OK/Enter" one time.
7. Press the left arrow key until TV type says NTSC and your picture is normal.