Hi! sadly, those Cinematronics Vectorbeam monitors are either tough or impossible to fix these days. We stopped selling the Cienmatronics games 20 years ago because of all the monitor issues. Sadly, they never built into the monitor any "safety" circuits to protect the monitor and make it shut down when there was a logic board flutter or issue. They were tons of trouble in 1980!
Happy 35 years Asteroids November 1979 - November 2014. And of course the cool side art and marquee is based loosely on the "Cylon Raiders" from Battlestar Galactica fame at the time. The back-glass for the Stellar Wars pin has this scheme as well.