I have an Intel motherboard running QNX 4.24. The power is controlled via a
momentary “soft” power switch on the front panel of the PC; this is a rocker
switch that when flipped briefly turns the power off and on. Under some
circumstances the system will fail in a peculiar way. The power light will
come on, but the video never gets initialized, and the boot sequence never
gets to load QNX. The soft switch becomes ineffective when used normally,
although there are some reports that if you press and hold the switch for a
long time, maybe 5 to 10 seconds, it finally takes effect. The only way
otherwise to turn the system off is to remove power physically from the
machine.
We suspect that there is a connection between this and some hardware on the
system, but, not knowing how the soft switch operates it is hard to draw any
conclusions. Has anyone else seen this type of behavior before, and can shed
any light? Barring that, can anyone explain to me how this switch works, or
point me at resources that might help? The Intel documentation is not
terribly forthcoming. I have a suspicion that it is connected to the System
Management interrupt somehow, and perhaps the System Management address
space is becoming corrupt. Even though the system doesn’t ever boot, the
fact that it eventually responds to the switch being held down implies that
SOMETHING is still active on the motherboard, paying attention to the
switch.
Any help or suggestions would be appreciated.
Thanks.
Kevin
You will probably find a setup in your BIOS that specified
how the button behaves.
This is a feature of ATX Motherboard/Power supply.
With these when you turn the computer off, not everything
is turn off. There is still power provided to some part
of the system. This allow implementation of wake-on-lan
and wake-on-ring.
\
“Travis McGee” <travmcgee@prodigy.net> wrote in message
news:8nr1v1$687$1@inn.qnx.com…
I have an Intel motherboard running QNX 4.24. The power is controlled via
a
momentary “soft” power switch on the front panel of the PC; this is a
rocker
switch that when flipped briefly turns the power off and on. Under some
circumstances the system will fail in a peculiar way. The power light will
come on, but the video never gets initialized, and the boot sequence never
gets to load QNX. The soft switch becomes ineffective when used normally,
although there are some reports that if you press and hold the switch for
a
long time, maybe 5 to 10 seconds, it finally takes effect. The only way
otherwise to turn the system off is to remove power physically from the
machine.
We suspect that there is a connection between this and some hardware on
the
system, but, not knowing how the soft switch operates it is hard to draw
any
conclusions. Has anyone else seen this type of behavior before, and can
shed
any light? Barring that, can anyone explain to me how this switch works,
or
point me at resources that might help? The Intel documentation is not
terribly forthcoming. I have a suspicion that it is connected to the
System
Management interrupt somehow, and perhaps the System Management address
space is becoming corrupt. Even though the system doesn’t ever boot, the
fact that it eventually responds to the switch being held down implies
that
SOMETHING is still active on the motherboard, paying attention to the
switch.
Any help or suggestions would be appreciated.
Thanks.
Kevin