NTSC Colecovision with no output signal, slight audio hum

I recently picked up a colecovision. However I'm having issues I can't quite solve. The power supply with works, it was tested on another system, but I get absolutely no video signal. When I turn it on, my TV still displays the classic channel 4 fuzz. Doesn't make any indication that the system powered on. The sound however slightly changes to a quieter buzz.

My thought is the Rf modulator is no good. I tested the voltage coming off the switch in the on position, and get 12v and 5v consistently. My TV isn't the issue since my NES and 2600 work no problem.

My thought was perhaps the composite mod could solve the issue by bypassing the Rf video chip and circuitry altogether.

I'm sceptical that the Ram is the issue, as from what I've seen you would still usually get some sort of video signal.

Any thoughts on what else I could check? Anybody have this issue before? I've watched probably 3 hours of CV repairs, but nothing with absolutely no video signal.

 

Maybe try not using the old Rf modulator? I've got a Colecovision myself and I just use one of these and a simple video cable.

Might not be any help but either way good luck getting it working proper.