If the Humax was working via HDMI before I can't see why it shouldn't still be OK. Have you tried it in the TV's other HDMI port, or used Scart instead? As for the RF connections, newer units don't have an RF modulator fitted - all they do is use the incoming signal for the tuner and pass everything straight through to the output. This means that you have to use the Scart~A/V~HDMI connections to watch anything you've recorded. I also understand that you can't "Daisy Chain" HDMI's - there is a built in detector to stop more that one device (this is to stop people making high quality copies). You might be better off employing a Scart or HDMI switchbox and just selecting the unit you want to view. If you need to record from the Humax this should be possible via the Scart connections and choosing an alternative input on your recorder.