Bally The Addams Family (Bally, 1992) GREED/Bookcase Issue

[bergytown]

Does anyone know why the Greed challenge on my Addams Family turns on each of the letters so quickly? Sometimes all i have to do is hit the left flipper button and it will tick off each of the letters one by one: G - R - E - E D.

Other times it will just tick off as i hit other targets. I just got this pinball a month ago and just ran past the warranty. this is my first pinball and do not know how to fix it. Please help if you can!