Motherboard USB ports staying live when PC shutdown - configurable?

[GidRea]

Hi Folks, I'm after some advice...

My PC is driving two monitors, 24" decent ones, but not new, 2014 or so. One on HDMI, one on DP. And, I have a mains-powered sound system. I got fed up with powering all these devices up and down, or rather, forgetting to. One of the monitors especially, goes into an annoying continuous test mode if the input signal is removed, I have to manually power it.

So I bought a main extension block, that has an additional, USB input connector (call this USB sense). The five three-pin socket outlets are only made live when the USB sense detects a live USB port. So, the PC automatically switches its peripherals' power, without any software being required.

Well. It almost works. But not quite. I'm wondering if some subtle setup options might exist in the motherboard's USB. I haven't looked, as I've no idea what the feature is called. Here's what happens now:

When I say the PC is "shutdown", I mean it has done Windows shutdown, but the PSU is still turned on, so the "power" button is able to turn the unit on.

When I say "turned off", I mean it has shutdown, then I've turned off at the rocker switch on the PSU.

1. PC was shutdown with USB sense not connected to PC USB: Plug in the USB sense: The sockets stay off. Deduction: The motherboard USB socket is NOT live. Press PC "power" button - PC fires up and peripherals are powered on.

2. PC was shutdown with USB sense connected to PC USB: The sockets stay on. Deduction: The USB socket is live. Deduction: If the USB socket is ?taking current? at shutdown, it is kept powered up on shutdown.

3. After 2. Turn off PC. Peripherals are depowered.

4. After 3. Turn on PC, but don't press "power" button. Peripherals are not powered.

(nice little finite state machine, where's my drawing tool?)

I have no reason to believe the extension block needs to understand USB signals, since the requirements should be achievable able from simple voltage monitoring. I can't see any USB connection for the extension block.

So, in summary, it is mostly what I want, except that apparently, if the PC's USB socket is in some way active at shutdown, it is kept in some way active on shutdown. I want shutdown to completely deactivate the USB port.

So: Is this a configurable behaviour, and if so, what's it called/where is it?

PC spec posted below my sig.

I believe (without moving PC & opening it, somewhat inconvenient at present), that I'm using one of the motherboard's USB sockets, as described below. Certainly the extension card's USB sockets are some way away - I haven't tried those, I'm hoping to get better informed first.

Many thanks
Gideon

PC Spec (Oct 2021):
Processor (CPU)
AMD Ryzen 7 5800X Eight Core CPU (3.8GHz-4.7GHz/36MB CACHE/AM4)
Motherboard
ASUS® TUF X570-PLUS GAMING (USB 3.2 Gen 2, PCIe 4.0, CrossFireX) - ARGB Ready!
Memory (RAM)
16GB Corsair VENGEANCE DDR4 3600MHz (2 x 8GB)
Graphics Card
6GB ASUS DUAL GEFORCE RTX 2060 - HDMI, DP, DVI
1st M.2 SSD Drive
500GB SAMSUNG 980 PRO M.2, PCIe NVMe (up to 6900MB/R, 5000MB/W)
1st M.2 SSD Drive
256GB PCS PCIe M.2 SSD (2000 MB/R, 1100 MB/W)
Power Supply
CORSAIR 650W TXm SERIES™ SEMI-MODULAR 80 PLUS® GOLD, ULTRA QUIET
Power Cable
1 x 1.5 Metre UK Power Cable (Kettle Lead)
Processor Cooling
Corsair H100x Hydro Cooler w/ PCS Ultra Quiet Fans
Thermal Paste
STANDARD THERMAL PASTE FOR SUFFICIENT COOLING
Sound Card
ONBOARD 6 CHANNEL (5.1) HIGH DEF AUDIO (AS STANDARD)
Network Card
10/100/1000 GIGABIT LAN PORT
USB/Thunderbolt Options
2 PORT (1 x TYPE A, 1 x TYPE C) USB 3.1 PCI-E CARD + STANDARD USB PORTS

 

[TonyCarter]

I've got the same motherboard as you, and had a similar problem where my USB-powered 'sensor' screen sat showing rainbow colours when I'd shutdown the PC.

I found there was a BIOS setting which lets you select whether the USB ports stay 'alive' during normal shutdown (i.e. from Windows, not from PSU)...I think it was something like "USB Power Delivery Off State S5" (will double-check where it is in my BIOS).

The setting (to be changed to 'Disabled') can be found in the BIOS at: Advanced -> Onboard Devices Configuration -> USB power delivery in Soft Off state (S5)

 

[GidRea]

Thanks, that sounds brilliant. I'll sit on it for a tad, then experiment.

I also realised that I own a USB power monitor (shows voltage & current), that I bought because my bicycle's dynamo has a USB output, but, unsurprisingly, rather erratically. Anyway, I can use it to spy externally and see what the ports are doing.

Actually, it'd probably be good to power down the peripherals in sleep, as well. But that'll be another state: Still I know where to start now.

 

[GidRea]

Yes, Tony, as you say, there it is in section 1.6.4 of the BIOS manual...

TUF GAMING X570-PLUS｜Motherboards｜ASUS Global

TUF Gaming series distills essential elements of the latest AMD and Intel® platforms, and combines them with game-ready features and proven durability. Engineered with military-grade components, an upgraded power solution and a comprehensive set of cooling options, this motherboard delivers...

www.asus.com

And, that also implies I can't have the peripherals turned off when the PC is asleep. At least, not by that method. Perhaps it would work in hibernate, since I guess in hardware terms that's like soft-off. For me, the problem with using shutdown is that we have more than one W10 user, and if the PC is sleeping, I don't necessarily know which/how many users are logged on, I don't want to lose their work.

I should have a separate PCI-E USB card as well (I'm not sure why I specified this, now that I realise how many USB ports the motherboard has that can be brought out, perhaps there wasn't a build option to have them out). Anyway, I suppose it might be separately configurable, although I can't identify it in W10 Device Manager.

I'll keep on...

 

[GidRea]

Belated follow-up.

I did look into the BIOS settings, as discussed, but didn't do anything in that vein.

Because, as per my last above, I had for some reason specified an extra USB board, perhaps I overlooked that the motherboard has about a gazzillion USBs. Anyway, when I plug the power controller's USB into a USB connected to the additional card (to be pedantic, that I believe to be on the card, but didn't open up to check), then it all works as desired. The two monitors are de-powered when the PC sleeps (or shutdown), and powered up then it is woken or started.