Keysight E4980A Service Manual page 56

Troubleshooting
Function Specific Troubleshooting
Figure 4-12 Handler Interface Function Check
Step 13. Press the TEST STOP softkey.
Do not execute any SELF TEST except for the Handler Interface Test or the
E4980A/ E4980AL will become inoperative.
Step 14. Return the jumper and switch settings on the handler interface board to their
original settings.
56 Keysight E4980A/E4980AL Precision LCR Meter