Hello,
Googled UFO pinball machine, and this post came to the top. If you're still trying to get it going, I own a working model. A little history: They were sold out of the J.C. Penny catalog, this was the lower mid-line available and it was circa 1977-78. It is loud with noisy functions. Basic home fun. If you are interested I can pull from storage and give a pic of the power supply data plate?