We bought a new TV for our room and we want to hook our old Motorola HD box to the TV. We hooked up the box to the TV using an HDMI cable. We get a picture but can't get any sound. We tried hooking up the old AV cables and we get sound and picture but then you can't bring up the cable guide or bring up the menu from the remote. We also tried having the audio cords connected at the same time as the HDMI cable but that didn't work. It seems like the audio and video AV inputs only work through the AV input.
The HD box has an old screw on end (like the old parallel port printer connection). I wonder if this is part of the issue? The instructions on the TV show the HDMI cable with the small, plug-in ends on both sides of the cable.