Power supply unit buzzing

[j7n]

I recently replaced my power supply unit. The model is Fortron "Hydro K Pro" HP2-500. Every once in a while it emits sharp AC buzzing. I can hear it when listening to music quietly or watching a film. The buzzing occurs at regular intervals: sometimes 10 seconds buzz, 10 seconds silent, and in other times 4 seconds buzz, 10 seconds silent. To check if was receiving a square wave on the power line, I turned on a second PC, which was silent as expected. It seems to be keeping this time internally and not responding to changing load. It can go for hours without buzzing. When on standby, the PSU buzzes quietly if I put my ear right next to it.

What is up with that? Is this what PSUs now do?

The power supply boasts a DC-to-DC converter and promises the full power on 12V, and has a fancy black circuit board with very few big caps. I am not capable of doing in-depth diagnostics.

The sound is disturbing as if the device is about to fail.

[Dixel]

3 hours ago, j7n said:

I recently replaced my power supply unit.

How recently? Is it still under warranty? I'd RMA it.

[j7n]

It's been in use for about 1 week. I first noticed it buzzing on the second or third day. It is working, I can't say that it has failed. And I also don't have a warranty card for it.

[D.Draker]

If you're not capable of doing in-depth diagnostics, I'd say better get rid of it. It's simply not worth it.

It's a high chance it has an overload somewhere due to poor manufacturing process, besides 500W PSU isn't something to die for.

Or even waste your precious time.

[NotHereToPlayGames]

The "K" is also their cheap and low quality model.  Sometimes "you get what you pay for" so may have to opt for a higher priced unit.

[Dixel]

5 hours ago, j7n said:

It's been in use for about 1 week. I first noticed it buzzing on the second or third day. It is working, I can't say that it has failed. And I also don't have a warranty card for it.

In my country it's enough to just have a serial number of the unit (usually a sticker), I replaced items myself, no questions asked.

[Dixel]

On the other hand, even if you manage to replace, even the 750W model looks scary and cheap inside. Sorry for the article in a foreign language, seems the model is only for the Eastern countries' market.

https://www.x-kom.pl/p/698743-zasilacz-do-komputera-fsp-fortron-hydro-k-pro-750w-80-plus-bronze.html

[j7n]

Even cheap units of the past were never quite this empty. I remember people were alarmed about ATX12VO when it was announced. Seems like ATX 3.0 is this at its core. The metal case of the HP2 is thin and bends easily. For some reason they included 2x CPU and 2x GPU plugs on the same wires.

I replaced a FSP400-GHN. It was supposed to be for a retro PC, with quite a few molex connectors. But something shorted inside it. The big capacitor dead and, oddly, has a direct connection to the heatsinks of the power factor correction and primary. Somehow the PC wasn't damaged.

Fortron seem to have remove most of their serious models and gone with a retail/gamer marketing. It used to be a serious manufacturer, OEM for marked up gamer brands. I don't really want to spend more than €50 for this, as I only need about 250 watts.

[D.Draker]

5 hours ago, j7n said:

I don't really want to spend more than €50

Under €50? Hmmm...

I've never got any troubles with the German Inter-Tech brand.

This el-cheapo model works in my spare server PC 24/7 for 5 years.

https://www.computeruniverse.net/en/p/90559458