The answer to 'ductless system not working' is that there are several common causes, including refrigerant leaks, issues with the compressor or fan, or problems with the electrical system. Symptoms may include the system not turning on, poor airflow, or uneven cooling. Solutions can range from simple DIY fixes to more complex repairs that require a professional HVAC technician.
If the system is not turning on at all, it could be an issue with the power supply or a tripped circuit breaker. You can try resetting the breaker or checking the power connections. However, if the problem persists, it's best to call a professional to diagnose and repair the issue.