EOS 7D External HDMI Monitor setup

[tmorgan_2100]

I'm using two Canon EOS7D cameras for filmmaking.

My plan is to set up the two cameras linked to an A/B switch on an external monitor, so I can see the output from both cameras simultaneously.

When I plug the HDMI cable (using an HDMI -> MINI HDMI adapter) into my cameras, the viewfinder on one begins flashing. Neither camera seems to send output to my monitor.

Is there anything I should check to set this up? When I use the port to connect to my computer via USB, everything works fine.

[Waddizzle]

You're not getting replies. Perhaps a little more info would help. 1. Have you checked, and what is, the setting for "Control over HDMI" in your camera? 2. Does the monitor work properly when it is connected directly to just one camera, or the other? 3. Did the problem you describe occur with, or without, the A/B switch? 4. Does your monitor have multiple inputs? I have experienced what seem to be ground loop issues when connecting mulitple HDMI sources to one particular monitor in the past. I've never figured out what the issue was because I was using top name, gold-plated cables. I suspect that my HDMI inputs were not ground isolated from one another. Connecting both devices simultaneously would cause both HDMI sources to go haywire and blank out. Never had an issue with just one HDMI source connected. I eventually went with one HDMI and one NTSC cabling.