I was asked to fix a problem with a karaoke set up at the local bar.

The problem is that when we plug the large screen TV in as a monitor, it causes audio feedback through the karaoke speakers.

Keep in mind, there is no audio going to the TV, only video.

The only things I can think of are to make sure the karaoke system is plugged in to the same circuit as the tv. And if that fails possibly rout the video through a VCR first, and then to the TV.

Any other ideas as to what could be causing it and/or what to do to stop the feedback?