An AC that goes from working fine to completely dead — no power, no response from the remote — is understandably alarming. The good news is the cause is often electrical rather than a major component failure.
A tripping circuit breaker (MCB)
If the breaker for the AC circuit keeps tripping, it's usually a sign of either an overloaded circuit, a short somewhere in the wiring, or the compressor drawing more current than it should (often due to an aging capacitor). Repeatedly resetting the breaker without finding the root cause risks damaging the wiring or the unit further.
A broken or damaged power cable
Cables exposed to years of heat, moisture, or rodents can develop breaks that aren't visible from the outside. This is more common in outdoor unit wiring that runs along exterior walls.
A failed capacitor
The run/start capacitor helps the compressor and fan motor start up. When it fails, the unit often won't power on at all, or it hums briefly before shutting down — this is one of the more common "sudden death" failures and is usually a quick, affordable part replacement.
PCB (control board) failure
The main control board can fail due to power surges, moisture damage, or simply age. This is a less common but more serious cause, usually requiring the board to be repaired or replaced.
What we recommend
Don't keep resetting the breaker repeatedly — if it trips more than once, turn off the AC at the breaker and call a technician. Diagnosing exactly which of these is the cause requires proper testing equipment, which is why a proper inspection is the fastest way to a permanent fix rather than guessing.