Solved USB port doesn't turn off

johnml49 · Jul 20, 2024

My motherboard is Asus Prime Z590M-Plus. I have a fan installed externally in the cabinet enclosure plugged into the USB port on my computer. The fan remains on even when my system is shut off. I have tried some recommended changes to Windows power settings with no success. See below:

Any help would be appreciated. I was wondering if I should be looking at the BIOS?

Thanks,
John

Shutdown via Command: Open the Command Prompt as an administrator and run the following command:
shutdown /s /f /t 0

This will fully shut down your PC, closing any hindering applications 1.
Disable Link State Power Management:
- Press Windows key + R to open the Run dialog.
- Type control.exe powercfg.cpl,,3 and hit Enter.
- Click on “PCI Express” and expand “Link State Power Management.”
- Set it to “Off” and click “Apply” and "OK"1.
Turn Off Fast Startup:
- Press Windows key + R again.
- Type powercfg.cpl and hit Enter.
- Click “Choose what power buttons do.”
- Under “Shutdown settings,” uncheck “Turn on fast startup (recommended)” and save changes 2.
Disable Hibernation:
- Open Command Prompt as an administrator.
- Execute: powercfg -h off to turn off hibernation 2.
Enable Hibernation (if needed):
- Type cmd in the search box.
- Right-click “Command Prompt” and choose “Run as administrator.

Berton · Jul 20, 2024

A Windows computer does not fully shut down until the power switch is held i for more than 6-8 seconds or all power unplugged and battery removed if a Notebook. It's a design change from the AT style motherboards from the '80/'90s into the 2000s to the ATX style. The power switch on the AT connected to the power supply and the power switch on the ATX connects to the motherboard and the power supply connects to the motherboard. The switch on the ATX tells the motherboard to get things started.

garlin · Jul 20, 2024

On newer motherboards, it's usually a BIOS setting to turn off USB power if the PC's not running. How it's done, depends on your brand & model.

[Motherboard] How to disable standby power of the USB connected device | Official Support | ASUS Global

johnml49 · Jul 20, 2024

Burton,
Thanks for your reply. If I press and hold the power button to shut down, is that a safe way to shut down, possibly if some applications are running?

Appreciate your help!!

bobkn · Jul 20, 2024

johnml49 said:
Burton,
Thanks for your reply. If I press and hold the power button to shut down, is that a safe way to shut down, possibly if some applications are running?

Appreciate your help!!

I'm not Berton, but: nope. Not 100% safe.

Holding down the power switch causes a forced shutdown. It probably will do no harm, but I believe that it can lead to corrupt files.

Some PCs keep power supplied to USB ports when the PC is down. That's intended for using the port to charge external devices. I'm unaware that a forced shutdown would stop that. (I'm not sure whether it's true.)

Later: I tried an experiment. I closed all programs, and held down the power switch to force a shutdown.

The PSU (be quiet! Straight Power 12 1500W ATX 3.0) seemed to still be supplying power to the motherboard. I didn't check any USB ports. Myabe the MB stopped supply power to the USB ports, but I didn't check that. I doubt it.

johnml49 · Jul 20, 2024

Berton, Oops, sorry misspelling you name.

johnml49 · Jul 20, 2024

Bobkn,
Thanks for your help. I think I'll just leave it as is!
Be safe.

John

FreeBooter · Jul 20, 2024

In BIOS, turn off ErP Ready setting.

bobkn · Jul 20, 2024

johnml49 said:
Bobkn,
Thanks for your help. I think I'll just leave it as is!
Be safe.

John

Things I neglected to mention:

It may be possible to disable the hot USB port feature in the PC's BIOS. (As posted by Freebooter. I'm unfamiliar with the terminology, as I don't use it.)

Your BIOS manual: https://dlcdnets.asus.com/pub/ASUS/mb/13MANUAL/PRIME_PRO_TUF_GAMING_Intel_500_Series_BIOS_EM_WEB_EN.pdf?model=PRIME Z590M-PLUS (There's a reference on p. 41 to disabling in the S5 "soft off" state, which appears to be a normal shutdown.)

I haven't found whether the charging capability is present on all ports. If not, you could just switch 'em.