Hi all, really hoping someone has an ideas about this as I been struggling with it for a while. I seem to have a short circuit that comes and goes. The layout is powered by an NCE SB5, to which 4 EB1 circuit breakers are fitted. A DCC bus (twisted pair) then goes round to the back of the layout, to 2 Tam Vally Depot boosters, which control the fiddle yard through 5 EB1 circuit breakers. The points are controlled through Megapoints system, but this fault happens whether its powered up or shut off. The points on the scenic side are electrofrogs, with Gaugemaster auto frog switches underneath. When it started, trains would randomly cause a short on the fast lines, circuit breaker 1 on the scenic side. At first I thought it was specific models, namely ones with TTS chips, but after some testing, its not that. I have Lenz, ESU, TTS, Lais and Hattons chips, and all can randomly be effected. Then I looked at the circuit breakers, swapped them over, changed which line they control, nope, not that either. I run a lot of older Lima stuff, so could the wheels be shorting the points? Nope, trains were cutting out on plain track too. By now the problem has migrated to the releif lines, which are on a different circuit breaker. The short is almost acting like a trickle short, it builds and builds until it trips. Some research I found the EB1s have a ridiculously short trip time, sound locos on start up can cause the factory set trip to time out , so I set them to a longer trip time. All the while, the short is coming and going randomly. Had some friends over and we had up to 8 trains running at one time for 6 hours, no trip, then it would all of a sudden act up for no reason. Then it would go away again. The other night, the problem seemed to manifest itself on the fiddle yard too as well as the scenic side. I by-passed the circuit breakers and everything run fine. No cut outs, but no gene smoke either from anything shorting out. I used to have termintion filters on the ends of each bus, as the layout is 45ft, there are sopme long runs, but a rebuild saw some of those disappear. I cant remember if these had an effect on it or not... Im completly stumped and its driving me mad! Any help would be greatly appreciated.