I'm not sure what it is you call a "controller". If it is the electrically operated valve, then you may be able to repair it yourself. You will need to know the brand and model. Depending on its location and access, sometimes a irrigation repair serviceman is your best bet. Yeah, I know is will cost some $$, but it could end up costing less to have a pro do it than DIY. As far as the leak is concerned, I have to assume the pipe that is broken is not part of the automatic irrigation system otherwise it would only leak when that particular zone was operating. Then only way you can find the leak is with a shovel. You just have to dig where the wet spot is. Pipes are laid in straight lines, so if you can determine where the pipe begins, and eyeball a straight line to the hose bib, you will have a line to start digging. Otherwise, just start digging in the center of the wet area, find the pipe and you should then be able to determine the direction to the leak. Digging out PVC can be tricky as a shovel can knock a hole in a PVC pipe fairly easily. Not much science to this, just common sense and shovel work. Once the leak is located, they make special couplers that make repairs very simple.