These are rebuilt, tested, and typically upgraded circuit boards that have passed John's Jukes Ltd.'s test fixtures and visual inspection. There may be minor visual flaws, but the boards are guaranteed to work in a working game. Warranty does not cover being blown up by existing problems in your machine though, but we will go gently with you if you consult with us about why you are planning on buying the board. Please email us through the Contact Us link and we should respond within 24 hours...