The answer to 'why is my mini split not turning on' is that there could be several common causes, including a tripped circuit breaker, a problem with the thermostat or remote control, or a mechanical issue with the unit itself. Mini splits, also known as ductless air conditioners, are efficient and convenient but can sometimes experience problems that prevent them from turning on.
If your mini split is not powering on, the first thing to check is the circuit breaker. Make sure the breaker has not tripped and that power is being supplied to the unit. You can also try resetting the breaker. If that doesn't work, the issue could be with the thermostat or remote control. Make sure the batteries are fresh and that the thermostat is set to the correct mode and temperature. If those simple fixes don't resolve the problem, there may be a more serious mechanical issue, such as a problem with the compressor or refrigerant leak, that will require the attention of a professional HVAC technician.