The answer to 'my air conditioner won't turn on' is that there could be several common causes, such as a tripped circuit breaker, a faulty thermostat, or a problem with the air conditioner unit itself. The symptoms may include the unit not powering on, no air blowing, or the fan not running.
Some potential solutions you can try yourself include checking the circuit breaker, replacing the air filter, and ensuring the thermostat is set properly. However, if the issue persists or you're not comfortable troubleshooting the problem, it's best to call a professional HVAC technician to diagnose and repair the issue.