PaulR

Not sure what you intend to with an HDMI "splitter".

HDMI switches don't split an HD signal so that you can see the result on multiple TVs or a TV and a DVD recorder. There is an electronic handshaking that takes place between the two devices connected by the HDMI cable and if this is not correct then the TV will show a blank screen.

I think the first thing to do is connect a temporary lead from your TV's sound output to the amplifier rather than the Humx. If that cures your problem then at least you know what you're up against.

PaulR As I get older I find myself thinking about the hereafter - I go into a room and then wonder what I'm here after.