RCA video "outlet" no longer showing...

Question

I have a JVC 3 disc karaoke machine which the RCA outlets for audio are working fine, but the video outlet all of a sudden stopped working. Is there anything I can do to troubleshoot the problem. I do not see anything visible inside the unit. There is a bit of color that will show, but alot of the wavy lines are on the screen so nothing really is visible.