I have a problem reseting 3 digits display working hours . I have used 3 passwords 149 / 221 / 501, None of them work. ( maybe the old service engineer has changed passwords). I have heard that i need Hiromatic display or Coldfire display , but im not certan anymore. Because i heard that old service engineer did not use them for reseting working hours. Can i reset working hours with 3 digit display? If i can , with what level password can i do it with?