I took the game apart. I dremeled off any corrosion /oxidation on the battery contacts and I bent the tabs that hold them in place so they dont wiggle around which ensures better battery contact. I also cleaned all the gameplay contacts. Game plays and sounds great.
See photos to see how it used to look. The item "Nintendo tabletop marios cement factory, taken apart, cleaned, new battery cover" is in sale since Friday, July 28, 2017.This item is in the category "Toys & Hobbies\Games\Electronic Games". The seller is "mattbarl_x8gqjug" and is located in Philadelphia, Pennsylvania. This item can be shipped worldwide.