Originally Posted by Hstl
Is there anyone who can give me a hint for this particular subject?
It is quite difficult to provide you with any hint since you have not said which kernel and X server you are using.
I had a Dell Latitude C600 until 2008 running Linux 2.4 and I don't remember such problems. The machine was using
APM for power management as ACPI was broken. Is there a /proc/apm directory on that machine ? Can you use apm commands to check battery level etc... ? Or is there a /proc/acpi directory ?
If your kernel is using ACPI instead of APM, you may have to blacklist the acpi modules and force the loading
of the apm module in /etc/modules.conf.
If your kernel does use APM, you may have to enable lid in the BIOS (unless this means that closing the lid
will shut down the computer. Maybe APM is deprecated in the kernel you are using (only ACPI can be used), and downgrading your kernel/distro may be the solution.
Finally, does your X server support DPMS (blanks/turns off the screen on inactivity) ? Use xdpyinfo to know that.