Contec Holdings Lt., a cable-box repair company owned by Boston private equity firm Bain Capital, is seeking bankruptcy protection. Founded in 1978, he Schenectaday, N.Y.-based company has listed debt of up to $500 million and assets of up to $100 million in documents filed Wednesday in U.S. Bankruptcy Court in Wilmington, Delaware, according to a Bloomberg report. “This reorganization process will allow Contec to invest in and enhance our capabilities to serve our cable industry customers,”…