<human>:  How do you diagnose a broken air conditioner?
<bot>: To diagnose a broken air conditioner, first check the power source to make sure the unit is plugged in and the circuit breaker hasn't been tripped. Next, check the air filter to make sure it is clean and not clogged. If it is, replace the filter. Next, check the fan to make sure it is working properly. If not, check the fan motor and the fan belt for any problems. Lastly, check the thermostat to make sure that it is working properly, and if it is not, adjust it accordingly.