I have an old HP Compaq 6000 running only Ubuntu 10.04. This was updated from 9.10. The current kernel version (?) is linux-2.6.32-27-generic. GRUB version is 1.98-1ubuntu9.

I apparently do not need a BIOS update for the MSI mb, since the only one available is for XP functions, as best I could tell.

At shutdown, the screen stays on after the system halts. The fans stay on, and the HD is not powered down.

I have tried just about all the suggestions I've been able to find, I can't remember how many, including acpi=force and apm=power_off additions to the grub.

Prior to stopping with a "System halted" notation, and an unblinking cursor, the computer says "acpid: exiting" and continues with other shutdown notifications. I don't know if that means anything or is normal.

Looking at the syslog, I have found this entry:
ACPI Error: A valid RSDP was not found (with some hex notation).

I know this is a longstanding problem, but I cannot resolve it with the info I've seen so far.

Hi batrot and welcome to LQ,

sometimes pressing the <ENTER> button helps when the power isn't automatically turned of.

Also you'll have to configure your Kernel in order to support "Power Off". There are settings in the ACPI section of the kernelconfiguration. You may google for "ACPI Power off".

Markus

I assume this configuration change is made by editing grub, and adding acpi=force and apm=power_off.

Those entries are in there, as suggested by some post I read early on. The cfg file I looked at said it should not be edited.

The only way to turn the computer off is to press the on/off button on the front of the unit.

BTW, I did try the "Enter" suggestion, but to no avail.