I've been using my Latitude E6410 for a few years now and it's by far the best laptop I've ever had.
Recently, my backlit keyboard stopped working. It's something that you don't appreciate enough until you lose it... So I got a new backlit keyboard for it and installed it, but it still doesn't work.
I wonder if it could be a problem that's unrelated to the keyboard itself - maybe some motherboard issue / bios bug / whatever. Or maybe the new keyboard I got has its backlit feature broken.
Please note it's been my computer for a while now, so I know all about how to activate it (alt+right arrow / bios setting). also note that it doesn't work even before the OS loads, where it used to work perfectly earlier.