I've got a Digitrax DCS 50 controller and it just started giving me problems runnning DC. It will run an engine for about five minutes and it starts to short circuit every few feet until it finally shorts. I've eliminated every other cause but the controller. I talks to George at Digitrax and he agrees something is failing and want me to send it back for him to test. It's long out of warranty so it's going to be at least $50 plus parts. It still runs fine in DCC but I'm concerned that this is the beginning of a general failure. Does it makes sense to have this one repaired or should I be looking for a new one?