hi Darkness,

I ran into a similar problem a while ago, and one trick that worked in most cases was this:
- boot up the receiver
- once it's up, navigate to Setup - System - Audio/Video - AV Settings (since the display is not working, either do this blind (menu-up-up-ok-ok-ok-ok on TNAP 4.2), or use the remote emulator in WebIF)
- change the resolution, press green, but when it asks for confirmation, click on no
- on my receiver the display usually starts working at that point, after a few seconds
- it seems to come down to HDMI negociation between TV and receiver, and this does not work with my old Sony (from 2006) but works with all my other TVs

of course the problem might be different in your case, but it's worth a try...