A mate of mine ( haven't seen him for a while ) used to work for LAI in the very early 80's and he remembers when they had a party to launch the new Gottlieb Black Hole to all the potential operators, and the bastard things were breaking down left right and centre.
I cant remeber how many they set up but about 4 of them broke down apparently because of "design flaws". How true that turned out be.