Short answer: If the indoor unit blows air but the outdoor unit is silent, the most common causes are a failed run capacitor, a burnt contactor, a tripped breaker or blown fuse, loose or damaged wiring, or on inverter ACs, an outdoor PCB fault. If the outdoor unit hums but the fan doesn't spin, the fan motor or its capacitor has usually failed.
What You Can Safely Check
- Mode: is the AC on Cool? In Fan mode, the outdoor unit stays off by design.
- Temperature: set it lower than the room temperature.
- Breaker: is there a separate MCB for the outdoor unit, and has it tripped?
- Wait three minutes: many ACs delay the outdoor unit after switching on, to protect the compressor.
Don't open the outdoor unit's panel; capacitors hold a dangerous charge even when switched off.
Faults a Technician Will Check
- Run capacitor: the single most common failure in Vijayawada's summer heat
- Contactor: pitted contacts, sometimes an insect trapped inside
- Wiring: loose or burnt terminals, damage from rodents
- Outdoor fan motor: compressor runs, fan doesn't, unit trips on high pressure
- Inverter PCB: after power surges or monsoon moisture
- Compressor: last on the list, after everything else is ruled out
