The answer to 'condenser not turning on' is that there could be several common causes, including a tripped circuit breaker, a faulty thermostat, a problem with the condenser fan motor, or a refrigerant leak. If your condenser is not turning on, you'll likely notice that your home is not cooling properly and the condenser unit is not running.
Some common troubleshooting steps you can try yourself include checking the circuit breaker, inspecting the condenser fan, and testing the thermostat. However, if you're not comfortable working with electrical components or refrigerant, it's best to call a professional HVAC technician to diagnose and repair the issue. Attempting DIY repairs on your HVAC system can be dangerous and may cause further damage if not done properly.