Dumbwaiter limit switch not working

Maxine Ave near Autumn, Corvallis OR

Description

My house in Corvallis has a dumbwaiter!! that recently won't stop when it reaches the top. Instead it reverses and returns to the bottom. I need someone WITH EXPERIENCE that can diagnose and fix the problem. OR please contact me if you know someone who can fix it. It has a control panel with relays, etc. Thanks.