Max,
I see that you submitted a support case. That is good. Our team will get back with you on Monday. I don’t see all the support cases, but I have not heard of this problem. We have seen some issues when powering HDMI splitters with “some” 7Ds, but not the monitor by itself.
I assume you have restarted the cameras by removing the camera battery for a few seconds.
Do you have the latest 7D firmware? We have heard that the latest firmware fixes some power related issues. I do not have any specific details.
-reed
Reed Phillips
http://www.SmallHD.com
919.502.7125