If there is no error that means it is working. How many comboboxes do you have in eachsheets.

Try to use this code, just seeing whether the code is invoked. It will alert "Hello I am working" if it is invoked.

Private Sub ComboBox1_Change()

msgbox "Hello I am working"

Sheets("Sheet1").ComboBox1.Value = Activesheet.ComboBox1.Value

End Sub