One of the features of the Dell XPS m1730 is the keyboard lighting. It often turn dark when working late again, which is fine. This laptop should have leds in the keyboard. But they're not working. By pressing the normal short-key for turning them on and off (Fn + ->) an icon is shown onscreen showing the state of the lighting, but the lights itself do not go on or off. I could find anything in the BIOS or in the Dell Quickset. Does anyone have an idea on where to look next?
As you've checked the obvious, (that the feature is turned on), it sounds like it's time to raise a support incident with Dell, as it could actually be a hardware fault that requires their technicians' help.