no signal when placing comcast box into Yamaha 7.1 system

I have a 2005 Yamaha RXV 1600 receiver. The Tivo that I had connected to it via an HDMI cable and an optical cable for Audio died. It only shows the splash screen and does not boot up. I took it out of the system and placed a Comcast Cable box model number XG2V2-P in its place using the exact same cables. I get no signal on the TV itself. I confirmed with Comcast troubleshooting that the cable box was visible on the network and that everything was working well. I took it out of that system and connected it back to the TV from which I had taken it and everything booted up properly. I put the tivo back in place and I can still see the splash screen. a professional installer opined that the cable box output was likely hdmi or hdcp 2.0 and my receiver couldnt deal with it, hence no signal at all. is there any way around this, aside from buying another tivo?