Comps nowadays push 5V out the ps2 and/or usb ports. Even when the comp
is powered off. Some comps have jumpers or maybe BIOS settings to turn
this off. But others don't. I have a comp that doesn't give me the
option to turn the 5V SB / 5VSB off.

How can I stop it?

I have an possible way. Cutting the 5VSB wire, it's the purple one -
pin 9
(googling atx in google images)
2 atx pinouts archived here
http://img201.imageshack.us/img201/9633/atx5di.gif
http://img430.imageshack.us/img430/5...pinouts0lu.gif

would it work?
would that mess up the MBRD?
would it mess up the PSU

I could always fix the wire back . No solder even required. Just
twisting a new bit in and adding some insulation tape. So i'm not
worried about that sort of "damage" to the PSU.

Standby voltage is usually there for a reason.

From the pinout I looked at
http://www.powerstream.com/itx-atx-pinout.htm, pin 14 (green wire)
turns on the supply. Try connecting pin 14 to pin 15 (ground) and see
if it the supply starts up. If it does, disconnect the standby Voltage
and then then try to attach it to a PC and try to turn it on. If the
supply doesn't run in a PC with pin 9 removed, the voltage is most
likely needed to make the motherboard work properly


wrote:
Comps nowadays push 5V out the ps2 and/or usb ports. Even when the comp
is powered off. Some comps have jumpers or maybe BIOS settings to turn
this off. But others don't. I have a comp that doesn't give me the
option to turn the 5V SB / 5VSB off.

How can I stop it?

I have an possible way. Cutting the 5VSB wire, it's the purple one -
pin 9
(googling atx in google images)
2 atx pinouts archived here
http://img201.imageshack.us/img201/9633/atx5di.gif
http://img430.imageshack.us/img430/5...pinouts0lu.gif

would it work?
would that mess up the MBRD?
would it mess up the PSU

I could always fix the wire back . No solder even required. Just
twisting a new bit in and adding some insulation tape. So i'm not
worried about that sort of "damage" to the PSU.

nvic wrote:
Standby voltage is usually there for a reason.

From the pinout I looked at
http://www.powerstream.com/itx-atx-pinout.htm, pin 14 (green wire)
turns on the supply. Try connecting pin 14 to pin 15 (ground) and see
if it the supply starts up.

connecting green and black(gnd). Well, i'd rather not have the PSU on
permanently. And I think doing so would cause that. Albeit low power.
I'll try just cutting purple first.

also, perhaps using 1 less GND wire may be problematic? Thre are so
many GND wires for a reason. e.g. one wouldn't want to cut them all and
use one. similarly, one wouldn't want to use one for something else.

I guess i'll have to try it.

I hope for a few more opinions confirming that cutting the 5vsb won't
fry the mbrd or psu.



If it does, disconnect the standby Voltage
and then then try to attach it to a PC and try to turn it on. If the
supply doesn't run in a PC with pin 9 removed, the voltage is most
likely needed to make the motherboard work properly


wrote:
Comps nowadays push 5V out the ps2 and/or usb ports. Even when the comp
is powered off. Some comps have jumpers or maybe BIOS settings to turn
this off. But others don't. I have a comp that doesn't give me the
option to turn the 5V SB / 5VSB off.

How can I stop it?

I have an possible way. Cutting the 5VSB wire, it's the purple one -
pin 9
(googling atx in google images)
2 atx pinouts archived here
http://img201.imageshack.us/img201/9633/atx5di.gif
http://img430.imageshack.us/img430/5...pinouts0lu.gif

would it work?
would that mess up the MBRD?
would it mess up the PSU

I could always fix the wire back . No solder even required. Just
twisting a new bit in and adding some insulation tape. So i'm not
worried about that sort of "damage" to the PSU.

wrote:

Comps nowadays push 5V out the ps2 and/or usb ports. Even when the comp
is powered off. ...

How can I stop it?

Plug the computer into a switchable power strip, and turn the switch
off.

Evil Homer wrote:
wrote:

Comps nowadays push 5V out the ps2 and/or usb ports. Even when the comp
is powered off. ...

How can I stop it?

Plug the computer into a switchable power strip, and turn the switch
off.

that is a no good solution. By that reasoning, I could switch it off at
the PSU (switch on the back), or pull the power cord out. But no good.

Attempting the cutting purple wire solution- the only option

I just tried it on a dead MBRD with no processor, comp didn't seem to
turn on. nobody fried. MBRD behaved as if the green and black were
connected i.e. it turned on. And no 5V SB. I'll try it on a decent
MBRD that I know turns on.

wrote:
Evil Homer wrote:
wrote:

Comps nowadays push 5V out the ps2 and/or usb ports. Even when the comp
is powered off. ...

How can I stop it?

Plug the computer into a switchable power strip, and turn the switch
off.

that is a no good solution. By that reasoning, I could switch it off at
the PSU (switch on the back), or pull the power cord out. But no good.

Attempting the cutting purple wire solution- the only option

I just tried it on a dead MBRD with no processor, comp didn't seem to
turn on. nobody fried. MBRD behaved as if the green and black were
connected i.e. it turned on. And no 5V SB. I'll try it on a decent
MBRD that I know turns on.

No, didn't work.

I tried it on the working MBRD, the PSU didn't turn on , so I attached
the green and black. The PSU turned on, the comp turned on too, but the
comp didn't sound like it was booting up . I didn't atach a monitor to
check properly. Even if it did boot up, it's not what I want because
the comp wouldn't turn off by the switch.

Somebody should make and sell an ATX power supply that works without
the 5V SB.

Somebody should make and sell an ATX power supply that works without
the 5V SB.

That would defeat the purpose of an ATX PSU, and in turn would produce
a non ATX compliant PSU.

In the other hand, the PSU is not the problem. The problem is the
motherboard design. No ATX motherboard will work without the 5VSB line
because it´s used to provide power to certain parts of the
motherboard, like the RTC, part of the turn on circuit, and so on.

lsmartino wrote:
Somebody should make and sell an ATX power supply that works without
the 5V SB.

That would defeat the purpose of an ATX PSU, and in turn would produce
a non ATX compliant PSU.

In the other hand, the PSU is not the problem. The problem is the
motherboard design. No ATX motherboard will work without the 5VSB line
because it´s used to provide power to certain parts of the
motherboard, like the RTC, part of the turn on circuit, and so on.


How about an electronic hack to remove the Ps2 and USB Wakeup. i.e.
Particularly the 5V that comes out those ports while the Comp is
powered down.

Some MBRDs and/or their BIOSs don't let you disable Ps2 wakeup.

That aspect of 5VSB is clearly not a necessity for an ATX MBRD to work.
Many even let you disable it. The problem is those that don't.

wrote:
wrote:
Bledge wrote:
In article . com,
wrote:
wrote:
nvic wrote:
Comps nowadays push 5V out the ps2 and/or usb ports. Even when the comp
is powered off. Some comps have jumpers or maybe BIOS settings to turn
this off. But others don't. I have a comp that doesn't give me the
option to turn the 5V SB / 5VSB off.

How can I stop it?
:
snip
:
I could always fix the wire back . No solder even required. Just
twisting a new bit in and adding some insulation tape. So i'm not
worried about that sort of "damage" to the PSU.

Standby voltage is usually there for a reason.

From the pinout I looked at
http://www.powerstream.com/itx-atx-pinout.htm, pin 14 (green wire)
turns on the supply. Try connecting pin 14 to pin 15 (ground) and see
if it the supply starts up.

connecting green and black(gnd). Well, i'd rather not have the PSU on
permanently. And I think doing so would cause that. Albeit low power.
I'll try just cutting purple first.

also, perhaps using 1 less GND wire may be problematic? Thre are so
many GND wires for a reason. e.g. one wouldn't want to cut them all and
use one. similarly, one wouldn't want to use one for something else.

I guess i'll have to try it.

I hope for a few more opinions confirming that cutting the 5vsb won't
fry the mbrd or psu.

Removing 5Vsb won't fry the mbd or psu.
You just won't be able to turn on the PC which may not be what
you want.

I would cut the 5Vsb wire and connect a switch to the cut ends so
that I can easily "reconnect" 5Vsb to the ATX conn. on the motherboard.
To make it convenient I would mount the new switch to the front panel.

I see, so I turn it on with the 5VSB, but then turn the 5VSB off once
the comp is on, and you say that will work. I could try that.

Yes, that would work perfectly.
You see, I am near the computer when I turn it on, but i'm typically
far away from it when I turn it off. By your method, I can shut it
down without driving my KVM(KVM Switch) haywire.

If you give up the RESET capability, and can find an ON/OFF switch
in the same form factor as the RESET switch, you don't have to drill
any hole in the front panel. You still need to solder the cut ends
to extension wires and then to the new ON/FF switch.


great idea, thanks.
I had to read that twice. I see, it'd be a good position to place the
"5VSB on/off switch".

I realise that I can't use the reset switch itself to switch the 5VSB
on and off. Because it only holds the circuit together as long as it is
held down. Infact, I reckon the power switch works the same. Because
one only needs to jumper whichever 2 pins for a moment, and the comp
goes on or resets.

Actually, why not switch off the mains switch?


It is turned on from near, but shut down from far away.
I have a KVM(KVM Switch), and a KVM Extender.
i.e. my computer box(es) are in one position of the house and i'm in
another with my monitor keyboard and mouse.

Many Thanks for your idea. I'll be giving it a go.

This is very exciting! I like electronics projects. Even simple ones.
I can't do complex ones, i'm only a computer techie - but i'm a
computer techie with a multimeter and a soldering iron ;-)


Actually, I can't see it working. If Ps2 runs on 5VSB, then when the
5VSB is off, it won't get the 5V it needs. It surely won't just swap
over to the 5V rail.

I suppose i'd either have to
- *somehow* amend the MBRD's ps2 thing to take the standard 5V instead
of 5VSB. Or,
-*somehow* remotely turn off 5VSB before turning the computer off. Or
even after turning it off. I wouldn't know how to go about either.
I suppose I could crack open the metal casing behind the ps2 connector,
and see if I get any ideas.
Or
- steal/use/cut the 5v wire from a 4 pin molex connector, thread it
out a hole in the case and into a ps2 cable that is plugged into my
comp's ps2 port.
So "5V of 5VSB" will be coming out the ps2 port, down the ps2 cable,
then a wire of the ps2 cable will be cut, and will continue with
regular 5V. Sounding a bit comical now. I suppose i'd have to ground
that end of wire receiving "5V of 5VSB" too.


Actually, no need for me to do any of that. I think it's only one funny
computer whose ps2 wakeup won't disable.
I will apply a similar technique to the one you mention.
I will put a 5VSB switch in , but not mounted at the front. The switch
will extend into my room.
immediately Before or after I turn the computer off, i'll turn the 5VSB
off.

I'll use shielded cable, so it doesn't act as an aerial. (I'm 20M away
from the box)

I'm not big on these things but I think 18 or 20AWM (thickness) like an
AC/DC adaptor wire thickness. Should be Dual wire, not strands. So
i've got 2 nice copper things going through. Should be shielded cable.
(I once tried extending teh switch of my KVM. I didn't use shielded
cable, and it had problems. apparently the wire acted like an aerial.
So i'll use shielded cable to prevent that. I'll ground the shield wire
of the cable on the comp case).


Thanks for giving your idea. I wouldn't have had this idea without it.

-----8---------------8---------------

Yes, that would work perfectly.
You see, I am near the computer when I turn it on, but i'm typically
far away from it when I turn it off. By your method, I can shut it
down without driving my KVM(KVM Switch) haywire.



-----8---------------8---------------

just looking at this from another angle, how exactly does this problem
manifest itself in the kvm going haywire?

perhaps a simple relay or transistor circuit could be rigged up to the
ps/2 port to disconnect it from the kvm when it detects - for example -
zero voltage in one of the 12v lines?