A minor problem PC won't shut down its power in AHCI mode
 

When I reinstalled Vista, I switched to AHCI mode aware that Vista fully supports it.

However now when shutting down the PC, even though Vista has shutdown and the monitor turned itself off, the PC refuses to shut its power off.

I'm sure there's nothing wrong with my hardware, since switching back to IDE mode would make the problem gone.

I remember somebody here suggested that I might forget to connect my north bridge and my southbridge but I don't see where I must connect the two. I thought they are already connected since I can read and write to my HDD just fine. Meaning the CPU and memory in the north bridge could interact and function with the SATA HDD and my DVDs which are using the south bridge.

Does anyone have any idea what could be the source of my PC refusing to shut down its power? The atx works just fine because if I switched back to IDE mode instead of AHCI the problem would be gone.

Let me guess... this is a DELL isn't it? If so, any problems booting in AHCI mode?

Sounds like your HD controller has an incompatibility with the mode. Vista may support it, but I have run into Dells specifically where it was a BIOS option that caused all kinds of issues from boot forward.

I would look to see if there is an updated firmware for the controller (though some are not flashable).

Worst case, stay with what works. Your not really gaining alot in reality making the switch.

Also - I seem to recall hearing you have to install in AHCI mode (the OS) for it to work right, so making the switch may be the problem as well. Not sure on that one though.

lol it's not Dell :har: I built my PC.
I've already installed the latest firmware. Actually at first few switching to AHCI there was no problem at all however in the past 2 reinstallation...the PC refuses to shut down its power in AHCI mode.

Reset or check the power options in the BIOS? Don't know if you changed anything there.

Vista has it's own power saving options set up as well. Look in there.

Thanks will do that.
I don't think it is the power setting as I just plaed with it and it brought no change to my problem

Problem solved.

I went to device manager
and under IDE/ATAPI controller were listed the following entries:

6 IDE channel
Intel(R) ICH9 4 port SATA AHCI controller
Standard AHCI 1.0 Serial ATA contoller
Standard sual channel PCI IDE controller


Note that there were 2 AHCI SATA controller. I disabled the standard AHCI 1.0 SATA controller since I knew that my motherboard is using ICH9 chipset for its southbridge chipset and voila now my PC could turn off its power once Vista has shut down.

Perhaps this could be useful.