Sounds like the arm itself is not earthed properly.
Do you have a continuity tester? If so, check the continuity of the arm metalwork (say at the headshell, not at the base) with the earth lead that plugs into the arm base.
Sounds like the arm itself is not earthed properly.
Do you have a continuity tester? If so, check the continuity of the arm metalwork (say at the headshell, not at the base) with the earth lead that plugs into the arm base.
Barry