When using a integrated display such as in laptops it will be great to have a display/video suspend mode. However I’ve checked this out by leaving the laptop without any interaction for >30 minutes but nothing happaned. How do I get the display to turn off automatically after a defined idle-time?
did you check the bios? and what happens when you close the lead?
If I close the display I can’t see anything 
There is no bios option so it needs to be controlled by the os.
Edit: the display is being disabled/off if i close it.
But I still would like to know if there is an suspend mode because I don’t want to close it all the when testing things and don’t want to have it on all the time.
I know the problem, I use a monitor what i can switch off and on.
can you use the function key and F9 or F10 or F11 key? depends on your type of laptop.
Function keys are not working and the brightness is always @ 100%.
Info about hardware?
Top secret: Lenovo T440s.
An IPFire box can see very short idle times, being constantly bombarded from the Internet. A preset idle period to turn display off is likely to be ineffective.
Do the Function keys work from USB keyboard ? If so, you could try the Fn, on laptop plus F on USB keyboard.
No no function key support at all with ipfire.
Idle for display suspend mode is always ment to be with timeout of hmi interactions.
That probably would require a window system and some power management that the console just does not have. It simply does not know that it is idle. It is possible to blank the screen (used in the past to avoid screen burn), but that is about it.
Ok good to know. So whenever I want to have the display off I need to close it. That’s ok.
Any Power management setups are available on UEFI?
The Fn plus F{n} key combination on a laptop should operate at hardware level and be independent of OS. What it does is dependent on the laptop model, but setting to “external only”, if that option is available, would save your internal screen and possibly some power consumption.
I can’t readily test this. The laptop that I use, as a fallback IPFire box, was ewaste having a broken screen, that I disconnected and removed.