Trace no-start and unusual-noise symptoms
A unit that clicks or hums without starting may have an electrical component or motor fault, while a completely inactive system may involve controls or power circuitry. The sound, timing, and operating state help direct inspection, but should not be used to identify a part without testing. Capacitors, contactors, and fan motors are distinct from compressor faults, so diagnosis matters before deciding whether a repair or broader replacement assessment is warranted.
