Fixing a broken heating and air conditioning system depends on the problem that is occurring, but often a system that is leaking water requires cleaning the drain from the drip pan. If the air conditioner is not cooling, clearing debris from around the condenser unit could help.
As the air conditioner cools the air, it also removes humidity. When the fan cycles off, the water that collects on the fan drips into a pan and drains to a floor drain or outside the home. If the drain line becomes clogged, the water doesn't drain and drips beside the unit. A straightened wire coat hanger inserted in the line helps clear any debris that collects near the end. A wet-dry vacuum placed over the exit of the drain also helps remove debris.
Weeds and debris that collect around the outside condenser unit make the unit less efficient at cooling. Removing the material restores the airflow and sometimes the cooling. Providing a shade that doesn't block airflow is also useful.
If the unit is not making any sound, the problem could be a tripped circuit breaker. Opening the electrical panel and turning the breaker off and then on again starts the unit operating. If the circuit breaker trips again, the best solution is to call for professional repair.