Combine potatoes, carrots, celery, onion and salt in a large soup pot; add broth to cover. Bring to a boil over high heat. Reduce heat to medium and simmer for 20 minutes. While soup simmers, place sausage links in a skillet; add enough water to come up halfway. Simmer over medium-high heat for 8 to 10 minutes, turning often. Remove sausages to a cutting board; let cool slightly and slice into rounds. Add sausage to simmering soup. In a small saucepan over medium-low heat, blend butter and flour; add milk. Cook, stirring constantly, until smooth and thick. Add milk mixture to soup; continue simmering until thickened. Stir in corn and beans; simmer until tender. Add cheese; cook and stir until melted. Makes 8 servings.