I bought my first G53J about 4 months ago, and it made me ecstatic (one of the best notebooks I've ever used). About 2 months later, the AC adapter pin in the laptop broke, so I received a new G53J from the store at which I bought it, where they replaced the Hard Drive with my old one.
This new laptop works identically well as my previous one, with one small exception: The backlights on the keyboard don't work. I know it's not a driver issue for the following reasons:
1) They worked on my previous laptop, and the HD is the same, therefore the driver is the same.
2) All other Fn functions work properly (e.g. Volume, screen brightness, etc.)
When pressing Fn+F4 (or Fn+F3 for that matter), my screen displays that the keyboard brightness is being turned up or down, respectively. However, no such light exists.
I also thought that it might have been incorrectly plugged in, as you have to take the keyboard out to access the Hard Drive. However, I also tried to plug it out, and then plug it back in myself with no result.
If anyone could help me out here I would be the happiest person alive.