Hi, we are currently using a Varian 3380 with an ECD to analyse PCB content in transformer oils. We have suddenly experiencing zero signal when running at the 1 range of the detector. Running on the less sensitive 10 range I do do get some signal but it's erratic. As I'm a bit of a novice when it comes to ECD's I haven't been able to diagnose the problem. Appreciate any help on this matter.