dont quote me on this but when i was in signal school we gotta chance to see new people come in and take the test. it was a simple series circuit that had a trouble and you would have to locate it (blown fuse, short etc...) and use the correct methods to fixing the problem but that was 2 years ago they could have changed it. but if you know how to trouble shoot which is the most important job of a signal maintainer then your gonna do great its a really simple test honestly