The answer to 'why is my AC not working' is that there could be several common causes, such as a dirty air filter, a refrigerant leak, or a problem with the compressor or electrical components. Symptoms may include the AC not turning on, blowing warm air, or making strange noises.
Some potential solutions you can try yourself include replacing the air filter, checking the circuit breaker, and cleaning the outdoor unit. However, for more complex issues like refrigerant leaks or electrical problems, it's best to call a professional HVAC technician who can properly diagnose and repair the issue.