There may be several reasons:

1. If there is a poor contact between the adapter power cord and the adapter socket, the cable should be replaced and the small metal column of the adapter socket should be cleaned.

2. The magnetic core of the switch transformer inside the adapter is loose, but it should not be handled. If you can't bear it, open it and add resin to the switch transformer.

The sound generated by current flow interference can be loud when some adapters are poorly shielded and do not affect their use.

3. It is not normal for the current adapter to have friction noise, after all, there is no sound producing device, which may be current noise. It is a normal phenomenon for a computer to have a slight friction sound inside, after all, it requires heat dissipation and continuous rotation, and there cannot be no sound. Power adapter is a power supply conversion device for small portable electronic devices and electronic appliances, which is widely used in telephone slave and master machines, game machines, language repeaters, Personal stereo, notebook computers, cellular phones and other devices.

The power adapter is generally composed of a shell, a power transformer, and a rectifier circuit, and can be divided into AC output type and DC output type according to its output type; According to the connection method, it can be divided into plug-in wall type and desktop type. Power adapters are widely used in various fields such as industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communication equipment, power equipment, instruments and meters.