Well, I think it's a challenge with analogue inputs, anyway.

So I've got a new(ish) Panasonic TH-P50V20Z.  Snagged it back when DSE and everyone else were doing ridiculous pricing on them, and have been pretty happy with it - just removed my older Samsung plasma, plugged in the HDMI, and never looked back.

...until today, when I tried to watch for the first time an older input - a component DVD player.  Nothing but a black screen.  Inputs are going through a Sony DA5200ES receiver that's set to upscale to 1080p.

Put the Samsung back in - seems to work fine.  So it's not the source, or the upscaling, but something to do with maybe the Panasonic not knowing what's coming over the HDMI cable.

Things I've tried:
1. Using component output; same problem, black screen (actually, worse - I can't get any image from digital sources either);
2. Using the monitor port on the receiver - component, S-Video, and composite.  Component and S-Video produce no image, composite produces an image until you try an enter the receiver's menu (at which point, black screen).  <- This scenario has no upscaling on through the monitor port.

I'm at my wit's end about what could be going on here.  It seems odd that the TV just won't work with analogue inputs because it's got a bunch of them on the back.

Thoughts or suggestions?

Thanks :)