Alienware 17-R2, power button no lighting?

I  have this issue where my Alienware 17-R2's power button led wont work anymore. it lights up while running the alienfxtester. but upon a shutdown and restart , still wont work. tried downgrading bios, reinstalling windows, power drain.. everything, no luck. does anyone know the fix? or is it something that dell needs to fix? Best Buy Geek Squad tried fixing the issue for 1 month and in the end they have no idea whats wrong.