A chirping noise is coming from my AC unit. I think it is coming from the fan motor. The squeaky chirping noise (sounds like a cricket) kind on cycles so that during a cooling cycle, the fan will go from making no unusual noise to this squeaky chirping noise and then back to no noise again. Do you think it is a motor bearing going out? If not, then what else could it be? Is this likely something I can repair myself, or do I need a professionals touch?