e moi nhan khach vao 1cay U700B. bỏ pin vao lên nguôn` dc. 1ti' roi tat, câp nguôn` vao` thi` kim dong len dên gân 1amp. co a e nao` da gap pan nay` xin chi cho e ! a e nao` co shema thi cang tot e xin chan thanh cam on.