My trix track is a very simple circle. Today, the model train suddenly couldn't pass through one of the straight tracks. I started to look for the cause and tested it with a multimeter. There was no problem with the power. I changed to another train and tested it, but the problem still existed, which meant that the problem was not with the train. Then I wiped the track with an alcohol sponge, but it still couldn't pass after the test. I don't know if there are other ways to find the cause?