If your Fluke 789 show "----" on the screen when sourcing or simulation current, this indicates that's there is an open loop. Possible causes include:
- An open fuse in the 789
- Test leads in the wrong jacks on the 789
- Open test leads
- An open loop
If the meter is able to provide a steady mA output, the problem is in the loop under test. You can check to see if the problem is the Fluke 789 by placing the test leads in the two left-hand jacks on the Fluke 789, selecting the mA output function , and shorting the leads together. If the display still shows "----", check the fuses and test leads for continuity and replace them if necessary. If the 789 still fails to show a steady mA output, it may need repair.