The answer to 'my ductless system won't turn on' is that there are several common causes, including a tripped circuit breaker, a problem with the thermostat, or a refrigerant leak. First, check the circuit breaker and reset it if it has tripped. Next, ensure the thermostat is set correctly and the batteries are working. If those basic troubleshooting steps don't resolve the issue, it's likely a more complex problem that will require a professional HVAC technician to diagnose and repair.
Ductless systems are complex appliances, and attempting to repair them without proper training and equipment can be dangerous. It's generally best to call in a licensed HVAC professional who can properly inspect the system, identify the root cause, and make the necessary repairs to get your ductless system back up and running safely.