I’m guessing the power harness for the monitor is hooked up wrong. Look at the connector make sure white goes to white, black to black and green to green.
Looks like your in luck http://www.ebay.com/itm/1989-KONAMI-Teenage-Mutant-Ninja-Turtle-Arcade-Game-Side-Art-Overlay-TMNT-NOS-/330684039357?pt=LH_DefaultDomain_0&hash=item4cfe4e00bd