Know this is going to sound basic, but have you
1. Checked all the cable connections including up on the roof at the antenna. You could also pull off the cover of the of the switch and check those three connections.
2. Make sure your antenna is up if you have a Wineguard, if you have a King Jack this is not a concern.
3. Make sure your tv is set to over the air before doing a channel scan, it is possible to get a few channels when set to cable as you have posted.
If these are ok you may have a bad cable, incorrectly connected cables, bad power booster, or antenna.