I built a new computer recently and I'm having trouble with
Sleep. If I set the BIOS to let Windows control it, sometimes
I can come out of sleep. (Win7 is similar. I get a black
screen.) If I set it for the BIOS to control sleep and wake up
from any keypress, so far it seems to wake up by pressing
the power button, but keypress has no effect. Has sleep
been redesigned on later systems? On XP it always works
and always wakes with a keypress. (I disable waking from
the mouse.) Is a USB keyboard perhaps a problem?

On 2024-03-18 15:21, Newyana2 wrote:
> I built a new computer recently and I'm having trouble with
> Sleep. If I set the BIOS to let Windows control it, sometimes
> I can come out of sleep. (Win7 is similar. I get a black
> screen.) If I set it for the BIOS to control sleep and wake up
> from any keypress, so far it seems to wake up by pressing
> the power button, but keypress has no effect. Has sleep
> been redesigned on later systems? On XP it always works
> and always wakes with a keypress. (I disable waking from
> the mouse.) Is a USB keyboard perhaps a problem?

The bios may have to be configured to leave at least the USB powered, at
least the port used for the keyboard.

--
Cheers, Carlos.

On 3/18/2024 10:44 AM, Carlos E.R. wrote:
> On 2024-03-18 15:21, Newyana2 wrote:
>>    I built a new computer recently and I'm having trouble with
>> Sleep. If I set the BIOS to let Windows control it, sometimes
>> I can come out of sleep. (Win7 is similar. I get a black
>> screen.) If I set it for the BIOS to control sleep and wake up
>> from any keypress, so far it seems to wake up by pressing
>> the power button, but keypress has no effect. Has sleep
>> been redesigned on later systems? On XP it always works
>> and always wakes with a keypress. (I disable waking from
>> the mouse.) Is a USB keyboard perhaps a problem?
>
> The bios may have to be configured to leave at least the USB powered, at least the port used for the keyboard.
>

It normally is powered, as the +5VSB powers the RAM during sleep,
and that same power source is used for USB ports. Something seems
to be able to cause USB devices to turn off their LED, yet there's
nothing I can see in a schematic that looks like a MOSFET on the
port VBUS. Some people claim they can't charge their phone off
a port, which implies the power is gated somehow. But the schematics
make it look like there is no gate on that power source.

Device Manager has tick boxes in Properties of a device, so that
some can wake the computer. Wake On LAN for example or Wake On Carrier
on the Ethernet. The keyboard and mouse are wake sources, with some
mice only waking on a button press (my Logitech), and others waking if the mouse
moves a pixel (which is not a particularly good idea). Armed mice, you can
see light coming from them during sleep (my Logitech turns off
the LED but the button sense is still on). The LED can flash, or, the LED
can remain on.

The nice thing about the Power Button on the front as an ACPI object,
is it tends to always work the Sleep control. That's assuming Sleep
was configured properly for basic operation (the power was left on
the RAM at shutdown). You could disable S3 in the BIOS, as an example
of a configuration mistake. Usually the BIOS is set to "S1,S3",
while on newer systems you don't have a choice, and that "S1,S3" setting
is used without a line being present in the BIOS screen.

When the fan stops spinning on the PSU, the +5VSB is still flowing,
and it stops flowing when mains power is removed from the guts of the box.
Either via using the switch on the back of the PC, or by pulling the plug.

Normally, Device Manager is configured with all waking sources set up.
And you turn them off, if they are waking the PC in an unexpected way
(such as the stupid Wake On Carrier setting on the NIC custom control panel).

The "powercfg" utility is chock full of fun stuff, for measuring the
properties of the machine. Maybe it could help at a time like this,
if something is broken.

Admin Command Prompt:

powercfg /?

Some hardware devices have declared in the past, that they are
not compatible with Sleep. And that can prevent a device from
sleeping, but it would probably come right back if you tried to
sleep it. It would not really go to sleep, and would appear to
wake up instantly.

If the motherboard BIOS has an ErP setting, you could try modifying that.
it's possible the BIOS can do something to reduce power further, but
this would not be something attempted during sleep (which uses 4 to 8 watts
with all RAM slots occupied). ErP was intended to reduce machine
consumption (via 5VSB) to 0.5W when the PC is not used but still
plugged in.

"ErP Support determines whether to let the system consume less than
1W of power in S5 (shutdown) state.

When the setting is enabled, the following four functions will become
unavailable: PME Event Wake Up, Power On By Mouse, Power On By Keyboard,
and Wake On LAN"

PME is the waking pin on plug-in Ethernet cards. One of the PCI Express pins
is a PME. It's possible PCI cards had a PME too, but modern motherboards
no longer have PCI (or AGP) slots. If you had a USB3 plugin card, waking
from its ports could be implemented via the PME pin on the edge card. But
I don't think the BIOS could do the right thing at shutdown (configure
the device, when the BIOS has no driver for such a card).

Paul

"Paul" <nospam@needed.invalid> wrote

| > The bios may have to be configured to leave at least the USB powered, at
least the port used for the keyboard.
| >
| Thanks to you both. It turns out there was a setting
to enable USB power, separate from the wake-on-keyboard
option. That seems to work now.