So it sounds like you have terminations on the splitter where cables aren't connected.
Sorry, I posted the picture because I had a question about the splitter itself & thought the picture would serve as a reference but I just middied the waters :-). I have a SWiM16 with two splitters -- the standard set up. I have all 4 DVRs & 1 Receiver already hooked up & working from a D* installation 18 months ago when Whole Home was first offered via DECA. I will soon replace one DVR with an HR34. From your pevious posts I am now comfortable with how I should set up the 2 splitters. However, when I looked at the splitters I couldn't tell how the cables go into them -- the ends didn't look threaded from what I could tell. I didn't take any tools with me when I went into the attic so I coouldn't try loosening a cable. I'll have to rearrange some of the cables to get the 6/6 tuner split & I'd like to know how to undo the cables from the splitters.
In the picture the single connector at the top is the input, which connects to the SWiM.
If you have a "standard install", you most likely have two 8-ways, which would look like the splitter in the lower right.
Looking at the 4-way in the upper right, you can see the one open port on the left, with three terminations on the ports to the right [the four on the bottom], so you'll need a 7/16 wrench to loosen and remove these where you have to connect a cable.