... panel(as drawn , Every figure represents a kind of function)1 .Working switch A( control A system)2 .Control mode A(converse ... .Control mode B(converse mode. Including 1,2,3mode)6. Play or stop(music switch)7 .Working switch B ( control B system)8 ... all the time) ,then open the switch(on back machine. red color), input four passwords (1,2,3,4 )reveal working number ...