During an air conditioner service, the technicians will check to make sure your air vent temperature is within the correct range.  They will also check your condenser and suction line temperatures to make sure they are also correct.  Your valves and thermostats will be measured to make sure they are working within correct parameters, and all of your hoses and components related to your air conditioning system will be checked to make sure they are in tip top condition and free of any leaks.  When necessary, the refrigerant will be evacuated and recharged, as well.  The condenser fins are usually cleaned and when necessary the technician will also adjust your drive belt and pulley.
After performing this check our technicians will discuss your repair options with you.