Faint hum from PSU even when PC is off?

  Bobtheblob 03:42 22 Jun 2007

I've noticed that on my new PC even when I shut down everything, there is a very faint almost inaudible hum coming from the back of the case. I assume it's the PSU. It only stops when I turn off the switch on the back of the PC or disconnect the power.
Is this normal?
As I say it's very quiet and only noticeable if you put your ear up against the case. Just wondering if it's something I should be worried about and if I should be disconnecting the power at night when not in use.
Many thanks

  ambra4 04:04 22 Jun 2007

A faint inaudible hum is the power transformer humming in the SP unit

Most power supply with a power switch supply power to the transformer at all times

The only way to stop this is to switch of the power supply unit

You should disconnecting the power at night when not in use.

There will be other who say you should not switch off the PS, I leave you to choice what you think is best

  laurie53 10:18 22 Jun 2007

Agree with ambra4. Disconnect the power at night. Even with the PC off the transformer coils are consuming a small (very small) amount of power.

This is costing you money and contributing to global warming.

The amounts concerned are probably infinitesemal but they all add up.


  Bobtheblob 11:59 22 Jun 2007

So the faint hum is normal then? My PSU isn't about to explode?
Will start disconnecting the power at night from now on.

  Quiet Life 12:12 22 Jun 2007

You may also find that the USB ports can have current with the computer off, but not disconnected, so power is also going to the motherboard.

  Fruit Bat /\0/\ 17:17 22 Jun 2007

IF power disconnected then CMOS battery holds settings in BIOS.

With power connected CMOS battery may last for several years, without the battery is used evry night and you will need a new in a couple of years.

If removing cards / memory on a modern PC you should always disconnect from the mains as power is fed to the board all the time.

This thread is now locked and can not be replied to.

Elsewhere on IDG sites

OnePlus 5 review

Alice Saey's mesmerising animation for Dutch singer Mark Lotterman

iPad Pro 10.5in (2017) review

Comment booster votre iPhone ?