Fans continuing to spin at low rpm when I shutdown.

TonyTurbo78 · 17 Feb 2020 at 18:53

Hi guys, not sure which forum to post this in. Hopefully you can help or at least point me in the right direction.

My 2nd gaming rig, my sim racing rig, when I shut down the pc I can still here the fans spinning at low rpm. What would cause this?

Also, because I have to turn the pc off by either rocker switch or at the wall, everytime I start the pc from cold I have to redo my nvidia surround for my triple screens. Would this be at all linked?

EsaT · 18 Feb 2020 at 11:14

Some PSUs have had feature which keeps their own fan running for short time to get rid of heat inside PSU.
You likely have such PSU.
Though not sure if some mobo might have feature which does same by using 5V standby to power fan outputs.

TonyTurbo78 · 18 Feb 2020 at 13:43

EsaT said:
Some PSUs have had feature which keeps their own fan running for short time to get rid of heat inside PSU.
You likely have such PSU.
Though not sure if some mobo might have feature which does same by using 5V standby to power fan outputs.

its not the PSU, its a 1200 Superflower. I have them in both of my rigs, it doesn't do that in my other rig.

I've looked in the bios but can't see anything in there either.

orbitalwalsh · 18 Feb 2020 at 13:46

TonyTurbo78 said:
its not the PSU, its a 1200 Superflower. I have them in both of my rigs, it doesn't do that in my other rig.

I've looked in the bios but can't see anything in there either.

temps are too hot it will stay on to cool the unit down - PSU anyways . if case fans thats a bit of an odd one. Only know that Bequiet flagship can plug in case fans to keep spinning for 5 mins on power down.

that or system hasn't actually fully powered own

ANDARIAL · 20 Feb 2020 at 08:54

Is the pc actually shutting down?
It is not on `sleep/hybrid sleep/hibernate ` is it?

Mr Mcgoo · 20 Feb 2020 at 19:33

is it possible you have a dehumidify option in your bios as my old z77 board had this option and would stay on with 5v powering the fans. This would spin the fans at a low rpm until humidity was reduce and repeat while on at the wall

Servo · 21 Feb 2020 at 12:21

Maybe fast boot could cause this

pete910 · 23 Feb 2020 at 14:32

TonyTurbo78 said:
its not the PSU, its a 1200 Superflower. I have them in both of my rigs, it doesn't do that in my other rig.

I've looked in the bios but can't see anything in there either.

Check the switch on the back of the PSU

I have a 1200 SF one and it will keep the fan on if it needs to if depending on where the switch is on the back

TonyTurbo78 · 23 Feb 2020 at 22:06

pete910 said:
Check the switch on the back of the PSU

I have a 1200 SF one and it will keep the fan on if it needs to if depending on where the switch is on the back

Oh, hmmm I didnt even know that was a thing and I've had those PSUs in both my rigs for a couple of years. Interesting. I'll give that a go tomorrow.

Thanks for the advice.

pete910 · 25 Feb 2020 at 23:10

TonyTurbo78 said:
Oh, hmmm I didnt even know that was a thing and I've had those PSUs in both my rigs for a couple of years. Interesting. I'll give that a go tomorrow.

Thanks for the advice.

Sort it Tony ?

TonyTurbo78 · 25 Feb 2020 at 23:19

pete910 said:
Sort it Tony ?

Sadly no. Flicked the switch the other way but the pump fans still stay on after shutdown. I thought it was all fans spinning at low revs previously but turns out its just the AIO fans on the rad. Something is clearly amiss.

pete910 · 25 Feb 2020 at 23:24

TonyTurbo78 said:
Sadly no. Flicked the switch the other way but the pump fans still stay on after shutdown. I thought it was all fans spinning at low revs previously but turns out its just the AIO fans on the rad. Something is clearly amiss.

Damn, Not PSU then, erm...

Is there an after run feature on the motherboard/AIO ?

TonyTurbo78 · 25 Feb 2020 at 23:33

pete910 said:
Damn, Not PSU then, erm...

Is there an after run feature on the motherboard/AIO ?

Not that I'm aware of. I cant see anything in bios, and there absolutely isnt anything like that on the NZXT KRAKEN AIO. I've the same AIO and PSU on my main gaming rig that doesnt do what its doing.

I've got the latest firmware on mobo also.

I might try moving the 4 pin to another header tomorrow.

pete910 · 25 Feb 2020 at 23:38

TonyTurbo78 said:
Not that I'm aware of. I cant see anything in bios, and there absolutely isnt anything like that on the NZXT KRAKEN AIO. I've the same AIO and PSU on my main gaming rig that doesnt do what its doing.

I've got the latest firmware on mobo also.

Has to be mobo keeping the AIO powered then, Thats all I can think of .

Are the USB ports still "Live" when comp is off, as in you can charge a phone or whatever ?

Most motherboards "newish" have the option to turn this option off/on , I know Mine does. (asrock)

Im only guessing that your AIO has a USB interface as well as the usual 4 pin header

TonyTurbo78 · 25 Feb 2020 at 23:53

pete910 said:
Has to be mobo keeping the AIO powered then, Thats all I can think of .

Are the USB ports still "Live" when comp is off, as in you can charge a phone or whatever ?

Most motherboards "newish" have the option to turn this option off/on , I know Mine does. (asrock)

Im only guessing that your AIO has a USB interface as well as the usual 4 pin header

I'll have a look at the USBs tomorrow.

Yeah the pump has a few cables. It has a 3pin to go to the fans, a 4 pin to go to CPU fan header on mobo and a USB-C (PUMP) to USB 2.0 header on the mobo.

LuckyBenski · 26 Feb 2020 at 07:47

Some RGB LED stuff stays on while the PC is shut down doesn't it? Maybe whatever causes that to still have 12V is doing the same to your AIO.

But then I don't have any RGB stuff set up yet so can't speculate much.

sadbuttrue · 28 Feb 2020 at 20:32

Believe it or not this is most likely your HDMI cable with its 5v pinout maintaining an active connection from monitor to PC.
My system does the same but only noticed recently due to it running 24/7.

TonyTurbo78 · 4 Mar 2020 at 22:48

pete910 said:
Has to be mobo keeping the AIO powered then, Thats all I can think of .

Are the USB ports still "Live" when comp is off, as in you can charge a phone or whatever ?

Most motherboards "newish" have the option to turn this option off/on , I know Mine does. (asrock)

Im only guessing that your AIO has a USB interface as well as the usual 4 pin header

Sorry for lengthy delay. Yes mate all the usb remain live after shutting down, I've little desk fans and phone chargers that I tested with.

Blinking annoying this. Theres nothing in the bios I can see about anything power related to shutdown.

peahead · 5 Mar 2020 at 00:13

Look for a setting in the bios called ERP and turn it on its normally located under power management options.

pete910 · 5 Mar 2020 at 00:25

TonyTurbo78 said:
Sorry for lengthy delay. Yes mate all the usb remain live after shutting down, I've little desk fans and phone chargers that I tested with.

Blinking annoying this. Theres nothing in the bios I can see about anything power related to shutdown.

In bios go to
Advanced >> ACPI >>> USB Soft off

Set to disable

Edit:

For some reason I thought you was using a ASrock board. So no clue where it is in your bios