"----" indicates there has been an electrical malfunction. Reset the Controller. See Controller Menu Setup - Service Procedure 15. If the "----" still shows, you will need to replace the Ascon Controller (part #A09).
Possible Causes:
There was a power surge. In order to eliminate this situation, plug the instrument into a surge protector.
This error can also be caused by microwave interference. Do not place the instrument near a microwave oven.