[PLUG] Shutdown won't power down

[Anthony Schlemmer]

To my knowledge it's not possible to get systems that use AT power 
supplies to power down unless the motherboard has some way to cut off 
the power coming from the power supply. The power switch on AT power 
supplies is connected directly to the power supply which is different 
than what ATX power supplies which use an electronic on/off in which 
the mobo can turn off the system via power management features.

You can see this with an ATX as if the power goes out it's possible to 
specify what the system should do when power is restored in the CMOS 
settings. I have my ATX systems set to stay off when the power comes 
back on. You can't do this with an AT power supply because as long as 
the power switch is in the closed position the system will power up 
when power is restored.

I have one system that still uses an AT power supply and I have to do 
special things when the power goes out to get the UPS that is connected 
to it to power down the system. If I don't do this my UPS's battery 
will be severely drained since the system will continue to run even 
though the operating system has already been halted. Draining the UPS 
battery below a certain point isn't a good thing to do since it can 
reduce the life of the battery.

An ATX power supply will continue to feed power to the mobo even when 
the system is turned off. I know most of my mobos have a red LED that 
is illuminated to indicate power is still being supplied to the mobo 
even when the system isn't powered on and running. This is why ATX 
power supplies also have an external switch on them so you can you can 
turn off the power completely to the mobo if you have to.

Tony

On Friday 10 January 2003 10:02 am, Kevin Cosgrove wrote:
> On 15 November 2002 at 10:09, Derek Loree <derek at infotects.com> wrote:
> > This is probably not the answer you are looking for, but I "fixed"
> > by powerdown by selecting the "use real mode to power down" option
> > while configuring my kernel ....
>
> For what it's worth "use real mode to power down" didn't work with my
> system (AT supply, Tyan Tiger MB, Mandrake 9).  At this point I think
> the supply just won't do that.
>
> Cheers....
>
>
>
>
>
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-- 
Anthony Schlemmer
aschlemm at attbi.com