I have an E5500 purchased through the outlet. The only feature missing that I wanted was the backlit keyboard. I purchased one and although the keyboard works, I can't get the backlight to work.
Although i can find several instances of people having difficulties with these items, no seems to definitivly know what is needed to upgrade to one after purchase.
Do I need an additional cable? Do I need to replace the palmrest at the same time? Should it just work?