Hi all Heres a strange one that took me a while to sort out.. just sharing the info in the hope that if you come across something similar it will save a bit of head scratching. 2 LG HD lcd tv's in customers house Each one works fine on its own (using aerial or scart input).. when both switched on, then rcd trips. When both switched on with aerials disconnected.. working fine. Connect aerial to one set only .... all is still ok Connect aerial to other set... trip The tv's are class 1 psu's (with leakage to earth, not measured as I didn't want to get blamed if testing caused the psu to fail). So whats the aerial got to do with it ?? It seems that the aerial connector on the tv is not at chassis potential so a few extra milliamps of leakage goes through the aerial. The reason. The chimney had 2 aerials.. (one was the neighbours) the aerial lashings were touching each other, the neighbours aerial was connected to a class 1 tv........... Doh !! The quick fix involved an isolated aerial outlet and a bit of cunning, the better fix will involve removing the existing lashing and replacing it with one that uses tape, but even better would be if LG either isolated their aerial connections or made sure that they were earthed.