I had the same thing. It works fine when I at my house but when i tried it at my tailgate I only got sound. It was a huge let down at the tailgate.
* Edited to observe Slingbox Answers Forum House Rules by Moderator. *
Hi, Rschack and hovdefamily
It seems that you are having some issues in order to get the video signal on the iPad.
If the set top box you are using attached to your Slingbox is using the HDMI cable, you will never get the video signal. The main issue is that the Slingbox (any model) and the HDMI cable are not compatible at all. The following link will provide you with further details and available options.