I recently acquired one of these but it does not work properly. The continuity works, but not the high voltage (250/500/1000V). A quick peek inside reveals nothing obvious but details of these seem hard to come by (schematics etc). I realise this is pretty niche, electricians will have moved on to much better/modern units by now, but for my hobby use I thought it would be useful. Any pointers on where to get some schematics would be appreciated, I am not sure I am up to reverse engineering it. It may be that the only way to fix these in the past was return to manufacturer and details have never been released. I will certainly do some closer inspections and checks though over the next week or so, thanks in advance. p.s. these are from the 80s/90s, the company was taken over and folded into Fluke, the name Robin lives on (was Robin Electronics Ltd). p.p.s. Other models 3010 and 3075 will share the same essential schematic.