So I don't know what order and for all the reasons you changed the boards you listed and I am sure you have done this, but have you cleared the digital board by pushing the red square button on the digital board? If so, did it not clear out the values on screen? From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of Harrold, Luke David Sent: Friday, February 03, 2017 10:26 AM To: [log in to unmask] Subject: [ISOGEOCHEM] Sercon 20-20 Misbehaving Ion Repeller Hello All, I am having a bit of an issue with my Sercon 20-20. It turns 23 years of age this month so I fully appreciate that it may have a few 'quirks' by now. After having issues with the focus amongst many other issues I have changed the source board, the digital board and the adapter board in the last month or so and I still have an issue with the ion repeller. When set at '0' I get a set point reading of '6.77' and an actual of '16.54', I changed the setting in the software to '-2' and the set points and actuals did not change. I have checked for continuity within the source itself and from the source board to the source and there is no issue. I am at a loose end now...help me...any ideas? Luke Harrold Research Technician Soil Isotope Group Office: G09 Labs: G.01,G.05 and G.34 School of Biological Sciences, Cruickshank Building, University of Aberdeen, St Machar Drive, Aberdeen AB24 3UU [cid:[log in to unmask]] The University of Aberdeen is a charity registered in Scotland, No SC013683. Tha Oilthigh Obar Dheathain na charthannas clÓraichte ann an Alba, └ir. SC013683.