> Are there multiple solutions to the conduit problem? Only I've done the 2 x 6 grid, found the broken circuits, but the two sets of answers that I've worked out don't work. I don't know where I'm doing wrong :-(.

There's only one solution that obeys all the rules. Remember to check all four of them: (1) all the links must point to each other in pairs; (2) you can go from junction to junction by following the links and visit EVERY junction (in other words, you form a single closed circuit -- it's possible to satisfy every other rule but this one and have an incorrect solution); (3) when traveling this circuit, every time you cross a parallel you must alternate crossing the outer parallel and inner parallel; (4) no links point across the broken conduits.