The answer to 'mini split not working' is that there are several common causes, including low refrigerant levels, electrical issues, or a problem with the compressor or indoor unit. Symptoms may include the unit not turning on, poor cooling performance, or strange noises.
For minor issues, homeowners may be able to troubleshoot and fix the problem themselves, such as checking the air filters or resetting the circuit breaker. However, for more complex problems, it's best to call a professional HVAC technician who can properly diagnose and repair the system.