I can not find the location of all those lights, well I don't have the actual laptop, so you would have to look around.
This is the still picture of XPS M1530 Diagnostic LED lights
And this is youtube link for the working video of flashing LEDs http://www.youtube.com/watch?feature=player_embedded&v=LUfvtKWIPWM
Which combination is applicable to you?
I hope this will help to solve your problem, once again the result can be very bad....