We have a Danfoss VFD breakdown ....the caoacitors burnt.We have a spare Vfd but we cannot access the parameters beacuse the password had been changed and no one knws what is the password. So we are using the spare VFD with the old control keypad and its card but we are getting a communication error . We checked all the parameters for communication according to manual. We suspect that the communication RS485 is not giving signal to plc.Is there any way to fix this.