What should I do if the compressor makes no noise?

The compressor is silent.

First, check the voltage: The voltage supplying the compressor should be around 220V (with an error margin not exceeding 10%, i.e., 198-242V). If the voltage is normal but the compressor shows no vibration and no humming exhaust sound, then measure the operating current. If it is ≤0.1A (the normal range should be 0.3-1.2A, with slightly higher current for larger refrigerators), the compressor has not started. Next, check internally: Measure the winding resistance of the compressor. The sum of the resistance of the running winding and the starting winding should be approximately equal to the resistance of the common winding (difference not exceeding 5%). If the resistance is too high (over 10kΩ) or too low (less than 1Ω), the compressor is faulty. Simply feel it: After running for a while, if the temperature of the compressor's casing is similar to room temperature (difference ≤3℃), it is likely not operating. Normally, the casing should reach 45-60℃ during operation, feeling warm to the touch.