Why is the power supply not working?

Question

Power Supply

Hello everyone, this is the situation.
There is a zalman zm500xe power supply, a year of work without any complaints, at one moment there was noise from the unit (not a fan), there is no picture, the fans on the case and the process are spinning, there are also superfluous sounds from the hard, like short knocks. I connected it to another PC, the situation is similar. When you turn on only the block with a jumper, there is a quiet squeak. I connected another power supply to the PC, everything works. Sent it back under warranty, everything is fine. Checked in a nearby service, everything is normal. That's all my authority is, all that's left is a socket, has anyone encountered such a situation and in what direction to look for a solution? Thank you.