Blown a fuse and watch how they fix it so you can do it yourself next time. It's about as simple as changing a light bulb and will save you heaps of money.

Check to see if the filter is clogged, if so clean it. If the metal fins on the back of the unit is clogged with dirt or a film like substance. Unplug the unit and use a spray cleaner like 409 on it. Let the cleaner set for 10 minutes or more and then spray out with a garden hose. Let unit set for 30 minutes, then plug in and see if it blows cold air. If it doesn't, then probably have a freon leak and need to replace the unit