|This is normally caused by dirty / faulty test leads. |
Please check out the reference value stored in the tester. To do this, rotate the dial to Autotest and press F3 to View Ref.
Figura 1. Ref from DSP-FTA440S
The values should be in the following range:
There could also be dirt in the adapter. Using alcohol and a lint free bud wipe, gently clean the inside of the SC adapters.