Computer exits sleep mode during static discharge


Y

Yousuf Khan

Okay, it's winter time here, relative humidity is low, so there's a lot
of static build-up on your clothes. Now, I've noticed that during those
static discharges, I can hear the computer immediately exits sleep mode.
Even if the discharge didn't happen anywhere near the computer, it may
have happened a room or two over, but you still hear the computer
powering up. Is it possible that a discharge could come *up* through the
grounding wires?

Yousuf Khan
 
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F

Flasherly

Even if the discharge didn't happen anywhere near the computer, it may
have happened a room or two over, but you still hear the computer
powering up. Is it possible that a discharge could come *up* through the
grounding wires?

Doubt it. Combination of predominately Windows' software and some
interaction given leeway for slight changes hardware manifests over
deviance from any sot of exacting precision programming them may, more
or less, expect. I'd expect we'd be programming them for sunspots as
well as grounding were it otherwise. You've a mouse/keyboard "human
device," some contingency within related hibernation devices that's
physically changed, faulting or out of specs, since initially
installed properly, if not a greater likelihood for software migrating
away from that original definition.

Ghosts in the Shell. Binary backups. A reinstall of Windows. Various
ways to interpret its humaneness, I suppose.
 
P

Paul

Yousuf said:
Okay, it's winter time here, relative humidity is low, so there's a lot
of static build-up on your clothes. Now, I've noticed that during those
static discharges, I can hear the computer immediately exits sleep mode.
Even if the discharge didn't happen anywhere near the computer, it may
have happened a room or two over, but you still hear the computer
powering up. Is it possible that a discharge could come *up* through the
grounding wires?

Yousuf Khan

Go to Device Manager and check the NIC properties.
There can be multiple Wake On Lan items to select
from. Make sure anything related to "carrier" is
disabled, as a static discharge may cause enough of
a "blurp" on the NIC wire, to trigger a rise from sleep.

I would start by ensuring that *all* Wake On LAN is
disabled. You can undo the setting later if you want.

The second step would be to carefully examine all
cables leaving the computer. Do you run a USB transfer
cable, that runs from computer to computer ? That
ends up connecting the grounds of the two computers
together, which is only recommended if the computers
are running off the same power strip.

Try to ensure the I/O wiring isn't contributing
to the problem.

We had a problem like this at work, and the root
cause in our case, was the reset wire inside the
computer case, acted as an "antenna". It would
cause the computer to reset, even during a static
event 20 feet from the computer. Since your return
from sleep, takes you back to Windows again, then it
probably isn't a reset, but a Wake event instead.
And I'm thinking the NIC is set to "wake on carrier
change" or something similar.

Paul
 
G

GlowingBlueMist

Okay, it's winter time here, relative humidity is low, so there's a lot
of static build-up on your clothes. Now, I've noticed that during those
static discharges, I can hear the computer immediately exits sleep mode.
Even if the discharge didn't happen anywhere near the computer, it may
have happened a room or two over, but you still hear the computer
powering up. Is it possible that a discharge could come *up* through the
grounding wires?

Yousuf Khan

If you have not already done so test the outlet and or outlet strip that
is servicing the PC to verify that it is wired correctly as well as
properly grounded.

It would not be the first 3-prong replacement outlet that was stuck into
an outlet box that was wired to only accept the ungrounded older 2-prong
outlet.
 
Y

Yousuf Khan

Go to Device Manager and check the NIC properties.
There can be multiple Wake On Lan items to select
from. Make sure anything related to "carrier" is
disabled, as a static discharge may cause enough of
a "blurp" on the NIC wire, to trigger a rise from sleep.

I would start by ensuring that *all* Wake On LAN is
disabled. You can undo the setting later if you want.

That does sound very plausible, but I do need to make use of the wake on
lan feature here, so I'm not going to disable it. But it does give me a
good theory explain it. It's not so much a problem as a curiosity.

Yousuf Khan
 
Y

Yousuf Khan

If you have not already done so test the outlet and or outlet strip that
is servicing the PC to verify that it is wired correctly as well as
properly grounded.

It would not be the first 3-prong replacement outlet that was stuck into
an outlet box that was wired to only accept the ungrounded older 2-prong
outlet.

Another good theory to check into, this is possible. The building I live
in was built back in 1976. Electrical wiring has hardly been changed since.

Yousuf Khan
 
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P

Paul

Yousuf said:
That does sound very plausible, but I do need to make use of the wake on
lan feature here, so I'm not going to disable it. But it does give me a
good theory explain it. It's not so much a problem as a curiosity.

Yousuf Khan

Yes, but WOL has as many as four "patterns".

Wake on Carrier is the stupid one.

Wake on specific pattern (the traditional WOL)
will still work, without being triggered by static
electricity.

It's the Wake on Carrier change that causes the problem,
because virtually anything can trigger it. And since
Ethernet wiring "floats" and there is no DC ground present,
there is a potential for the wiring to work as an antenna.
Not an efficient antenna, but the potential is still there.

I've placed a scope on Ethernet wiring, as part of my last
job in the lab. And you can see tens of volts of potential
(common mode) riding on an Ethernet cable. The transformer at
the end of the line, removed the common mode stuff. The input
looking at the other side of the transformer, should remove
a little bit of common mode. It would be things like parasitic
capacitance in the transformer, which might couple through the
static discharge. And disabling the Wake on Carrier, and using
some other pattern, will make the "key" to unlock sleep, that
much more complicated.

Paul
 
P

Paul

Y

Yousuf Khan

Yes, but WOL has as many as four "patterns".

Wake on Carrier is the stupid one.

Wake on specific pattern (the traditional WOL)
will still work, without being triggered by static
electricity.

It's the Wake on Carrier change that causes the problem,
because virtually anything can trigger it. And since
Ethernet wiring "floats" and there is no DC ground present,
there is a potential for the wiring to work as an antenna.
Not an efficient antenna, but the potential is still there.

I've placed a scope on Ethernet wiring, as part of my last
job in the lab. And you can see tens of volts of potential
(common mode) riding on an Ethernet cable. The transformer at
the end of the line, removed the common mode stuff. The input
looking at the other side of the transformer, should remove
a little bit of common mode. It would be things like parasitic
capacitance in the transformer, which might couple through the
static discharge. And disabling the Wake on Carrier, and using
some other pattern, will make the "key" to unlock sleep, that
much more complicated.

Okay, I might test it out, you got me curious. And I do have one 10m
(30ft) cable on this LAN, which might be the one acting as an antenna.

Yousuf Khan
 
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Y

Yousuf Khan

Okay, I might test it out, you got me curious. And I do have one 10m
(30ft) cable on this LAN, which might be the one acting as an antenna.

Alright, I turned on the feature called "Only allow a magic packet to
wake the computer". So far so good, seems to be keeping it from waking
up with a static discharge.

Yousuf Khan
 

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