I assume you mean that the C100s you have, using HDMI, will output to a typical modern TV HDMI input. But they won’t to a modern professional monitor HDMI input. Correct? Have you tried using a different HDMI cable? Has the C100 ever worked with the Pro monitors? Will the same cables successfully input signal from a different type of camera into the same monitors?
Why I ask is that if it never worked, is there some kind of setting on the pro monitor that isn’t set right?
The output is described on page 114 of the manual. There is a cryptic line that reads:
“Video might not be output correctly depending on the monitor. In that case, use the AV out terminal.”
I once found that the standard HDMI cables I was using did not work with my newer cameras. When I bought what was marketed as High Speed HDMI cable, which is what Apple claims is needed for the iTV, the cameras worked fine with the monitor. I was under the impression at that time that all HDMI was one standard. They aren’t.
The various types of HDMI cable are described here:
https://www.hdmi.org/consumer/finding_right_cable.aspx
Hope this helps.
Al