A missing package? If yes, which one?
 

Pressing the power button momentarily results in KDE not responding. I can get a terminal by pressing Ctrl + Alt + F1 to stop and restart kdm.

I want to be able to turn off my computer by pressing the power button. This never works.

I would recommend to start the computer, then turn off KDM, so that you will be dropped to the CLI. Now start KDE manually with , press the power-button and switch to the terminal where you started KDE, so that you can see if you get error messages.

I switched to a terminal, stopped kdm, and started kde using startx. Pressing the power button didn't yeald any information.

I changed a setting in kde power management to test whether the fault was caused by a faulty setting. Initially, kde was intructed to issue a system dialog whenever the power button is pressed.

If you wait for the Grub menu to come up and then hit the power button does it turn off?

I found that pressing the power button for longer (~1.0 - 1.5 seconds), is a workaround to the issue, although the shutdown sequence takes more than half a minute only to be initiated!

Definitely, something must be wrong. It can be the 128 pin power management IC, but I have no idea. I am planning to replace this damned IC, but I must first get hold of the right soldering/desoldering equipment.

Regarding the previous post asking about the functionality of the power button in grub, it should be noted that grub uses a different kernel stripped down to suit a bootloader. However, there is nothing wrong in testing during my next reboot.

Added Later:
When grub boots and shows its menu, pressing the power button does not do anything! However, if I hold the power button for more than 3 seconds, the laptop turns itself off.

Sounds pretty normal to me.

Hi,

sounds like you want to configure acpi. You can do this independently of kde. Have a look at /etc/acpi/powerbtn-acpi-support.sh (and other files in this directory). Also checking /var/log/syslog may help you see what is happening when you press the power button.

Evo2.

The power button should work in Grub, so this seems to be a hardware problem or a misconfiguration in the BIOS. Holding the power-button down for 4 seconds is some kind of emergency shutdown, so that this works means at least that the power button is working correctly.
Before changing ICs I would try to reset the BIOS and look if anything changes.