Yes, I have tried CTRL+0.
But, have you actually added a new camera to your scene?
Got to Add menu and select Camera. New camera will be crated at position of 3D coursor. Then press CTRL+0 to set active camera to that new camera. Now press NUM7 and then pres CTRL+ALT+0. Your new camera will be aligned to top view.
And for fun, you can press ALT+0 and you'll switch default camera back to first camera.

Cheers!