If my air conditioner return line iced over and the fan stopped, is it broken?
ice usually means either your air handler isn't pushing enough air across the coil, or your system is out of refrigerant.

so first step is to set the cool/off switch to off. then set your fan switch to on. if the air handler fan does not turn on, then you have a problem with your air handler or thermostat. possibly cheap. possibly something you can fix yourself.

otherwise, you probably have a problem with refrigerant (which should not deplete, and if it does then you have a leak somewhere) or your compressor. in either case, you should leave your system off to avoid damaging your compressor until someone can come out and look at it.