Not cooling traced to capacitor fault, not compressor failure

What we found

When the compressor won't start, it could be the compressor motor itself or something that helps it start. We checked both possibilities.

• Outdoor fan was running fine—that ruled out some issues
• Compressor was making a buzzing sound but not actually spinning—that's a key clue
• The sound lasted about a second, then the breaker cut it off
• This pattern pointed to the capacitor, not the compressor motor

The capacitor is like the starter in your car—it gives the compressor a boost to get spinning. When it fails, the compressor hears the signal to start and tries, but can't build enough power. You hear it struggling (the buzz), and the breaker shuts it down for safety. The motor itself was perfectly fine.

What we did

No compressor replacement needed. We replaced the capacitor, which is a smaller and faster repair. The compressor started normally right away.

After the capacitor replacement, the unit cooled perfectly. The customer avoided a much larger repair bill and got their aircon back in one visit. No further issues since.

What we learned

How to tell compressor failure vs. capacitor failure.

• Buzzing sound + trying to start = capacitor issue (usually cheaper fix)
• Complete silence + no startup attempt = compressor motor problem (more expensive)
• Testing tells the real story—what you hear is just the first clue