T C said:
Hello group,
I just rebuilt my machine with an asus p5gd2 deluxe, a 2.8Ghz proc.,
Crucial memory, an asus n6600gt video card. 3 case fans.
And the foolish thing starts up for no reason.
I checked the BIOS for Wake ON LAN settings they look OK.
I think ACPI has normal settings.
Anyone heard something like this before?
Thanks
TC
I've had that happen, when an IDE cable was only partly
inserted into the motherboard connector. Anything which
upsets the logic path that the power switch logic
takes, is a possible cause of the problem. If a chip
that contributes to the "wake" logic, is being tortured,
that will cause the board to turn on.
I would start by verifying the stuff wired to the PANEL
header. The easiest thing to do, is just disconnect all
the stuff on the PANEL header, and see if the computer
still starts on its own. That would be a quick check that
it is not a fault with the computer case switches.
It could even be the power supply that is at fault. If
PS_ON# ( a signal on the ATX 20 pin connector) is getting
grounded some how, the power supply will start right away.
You could do the cardboard test, and assemble the system
outside the computer case. That will give you an opportunity
to isolate the bottom of the motherboard, from anything
that could be shorting it from underneath.
You can start with just the motherboard and the power supply,
and no other components. The power switch should still work
properly, and you should be able to turn on the PSU by pressing
the power button for a moment, while switching it off could
take pressing the power button for up to four seconds.
Add components one at a time (pulling the power plug each time,
before adding or removing components - a safety precaution to
prevent +5VSB from damaging any components). Add processor,
memory, video card, monitor, disk, keyboard, mouse etc, taking
note after each component is added, as to whether your problem
has come back or not. Make sure the installed components are
inserted all the way into their sockets (sometimes the memory
doesn't seat well, the first time you install the DIMMs).
I like to assembly the system on a table first anyway, just
as a quick check that all the components are healthy. If
I can boot the system while it is sitting on the table, then
I consider it is worth spending the time to assemble all the
components in the computer case. A professional builder
wouldn't waste time doing that, but as a home builder, I
have the time to do it.
HTH,
Paul
