... cell phone cover,then screw,then screw down clockwise.3.Turn on light source swith(F)of microscope,put object lens ... lens(D) facing downwards.3.In time of insufficient light,turn on switch (F) to start up LED lamp (E) to ... (A)5.If image is not clear,adjust forcus-adjusting knob(C) left and right,until get clearest image.Replace the ...