Sorry to hear that you have no video/audio through your Slingbox Pro-HD.
Have a question for you, do you have a HDMI cable from your cable box to your TV? If so, check out the following articles:
- When I connect my set-top box to my TV with HDMI connections, I can't stream video at all using any version of SlingPlayer. Why?
If this is the issue you are seeing, you may have to eliminate the HDMI cables altogether and just run the Component cables to the Slingbox, this is explained in this article.
Hope this helps!!!
Sling Media Moderation Team