Dear Xiaoli I’m sorry to hear that you have trouble with your new purchased computer. The computer always shut down and appears blank screen. You asked to replace it after several useless repairs, but the dealer refused. I think you have the rights to ask the dealer to replace. I have some suggestions. First, you should keep the invoice and records of repair. You can show these to dealer and declare you have the right to replace. Second, you can complain the dealer to Consumer’s Association. Third, you can tell the news paper or TV, and let them to expose the dealer’s conduct. Last, you can accuse to dealer to court. Best wishes! Yours sincerely Li Hua