PSU is buzzing

Hello everyone! We bought an external modem here, and it came with an external power supply. Situation such that the transformer in this power supply hums just the worst So - very, very loud. It would probably be even more correct to say that he It doesn't hum, it crackles. But the power supply itself works normally. Situation is aggravated by the fact that there is no way to return the purchase or change under warranty, etc. In general, you need to live with this power supply or buy a new one. So here it is Before buying a new power supply, I would like to clarify if there are any folk remedies for eradicating such noise (drop varnish where necessary, insert some kind of gasket [not to be confused with women's ones] or something else)? Visually The transformer looks quite normal: no cracks, gaps, or looseness no. Or should I go to the morgue? Stanislav