Making iMac headless. iMac GPU & CPU issues

Hey Guys,

There are a couple posts on this but not conclusive to my situation so thought I would ask this anyway.

So I am using conferencing software called Zoom Rooms that would normally be setup on a limbless/headless Mac Mini with a projector as display for conferencing.

I have an iMac 27” with broken screen which can serve this purpose since it cannot be used for much else but, even with mirroring options enforced on the display settings the software it’s self recognizes 2 displays - the broken screen & projector, so that unfortunately participants cannot be seen on the projector.

There is a workaround in the software but it has to be manually set every time a meeting is started. I have tried disconnecting the iMac screen internally but what seems to happen is it uses the CPU for displaying to the projector and not the GPU causing the fan to go crazy and visuals and performance to be jittery and sluggish.

Is there a work-around for this issue?

I saw a post about a VGA hack using resistors but not sure if that would work due to the projector already using a display port > HDMI output.

I can see that a Mac Mini would not run into this issue due to it being designed to only use an external display via GPU and iMac’s quite the opposite.

Any info on this strange attempt at using a half dead mac would be greatly appreciated.