Start where the failures actually live. Airflow first: a filter past its life, a blower struggling, or returns blocked by furniture starves the coil, drops cooling, and eventually freezes it. A surprising share of no cooling calls end at this step, which is why any diagnosis that skips it and opens with a compressor is out of order.
In Mission Viejo, run the tract diagnosis before the parts cannon. Check the filter and the condensate drain first, because a clogged drain float switch is the silent killer in garage and closet installs here. Then read the capacitor after any Santa Ana heat day, since heat stressed capacitors are this city's signature summer failure. If the system cools the front of the house and not the back bedrooms, stop pricing equipment and start reading ducts: that pattern is distribution, and no new condenser fixes it.
Electrical second: the capacitor and contactor are the small parts that start big motors, and they fail on the hottest days because that is when they work hardest and longest. Gauges third: refrigerant charge is measured, and low charge means a leak to find, because refrigerant circulates in a sealed loop and is never used up.
Ducts last and often: cooled air dumped into an attic through a separated run cools the attic faithfully while the house complains. If one end of the house never cools while the other overcools, suspect the air's road, not the machine making it.
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