Strange shutdown/reboot behavior

[snarfies1]

Not sure if this is the best board to post this in, but...

A few weeks ago I built a new system:
Intel Q9450
Asus Rampage
Antec 900
Antec Neopower 650
Windows XP (x86) SP2 (now SP3)

When I shut down Windows, the system does not power off - it reboots. This occurs when I do it though the start menu and when I press the power button on the case. The only way to actually shut the computer off is to hold down the power button. If I do this during POST after reboot the BIOS freaks out with a failed overclock message (400 FSB and stable) when I turn the computer back on.

Any thoughts?

 

[godless]

maybe in power options you have it set up that whenever you click the shutdown button you reboot? i know i had it in my laptop whenever i told it to shut down, damn thing went into standby.

 

[evongugg]

It could be wired incorrectly. Look at the front panel wires on the motherboard.

 

[bobbknight]

In Bios:

Manual Reference;
Power menu 4.6 page 4-30 set power switch to off, and enable acpi 2.0 support.
Set your apm configuration to defualt per manual page 4-31, figure 4.6.5.
Make sure no case internal cables are pressing against the on board MB power switch.

Boot and try to shut off system by os.

 

[snarfies1]

Thanks folks, I'll check these things out when I get home. Which, unfortunately, won't be until later this week, lol.

 

[snarfies1]

No dice so far, system still doing the same thing.

maybe in power options you have it set up that whenever you click the shutdown button you reboot?

No, I checked, didn't see anything like that. Didn't even know you could set that sort of thing up. Or why you'd ever want to, given that there's already a perfectly good option to reboot.

It could be wired incorrectly. Look at the front panel wires on the motherboard.

Would that matter, though, given that I'm not using the power button to shut down? Would that not also prevent me from using the power button to actually turn the system on to begin with? I have a new card on the way so I'll open the system up again to install it and I'll look then, but...

Power menu 4.6 page 4-30 set power switch to off, and enable acpi 2.0 support.
Set your apm configuration to defualt per manual page 4-31, figure 4.6.5.
Make sure no case internal cables are pressing against the on board MB power switch.

4-30 has no mention of "set power switch to off" in the text or illustration, and the text and illustration match the actual BIOS screens, near as I can tell. ACPI 2.0 is enabled (I experimented with disabling it, Windows won't even entertain trying to boot without it, not even from an install disk). APM is as pictured on 4-31 (the default).