The Nduom family, a group of Ghanaian-American investors, has invested $9 million into Illinois Service Federal Savings & Loan Association, one of the last black-owned banks in Illinois. Brothers Chiefy and Kweku Nduom said the family plans to overhaul the Bronzeville lender, trying to put the bank's close call with failure behind it. Their father, Papa Kwesi Ndoum, is now chairman of the bank. Now that Illinois Service is better capitalized, it plans to focus on its technology, loan portfolio and to reconnecting with its neighborhood. Illinois Service, which remains under regulatory scrutiny, still must confront the challenge of dealing with a portfolio in which 13.4 percent of its loans are seriously delinquent.