Chosen Solution

Hi guys, So I’ve got a very weird issue. And I’m curious if you guys think it could be the keyboard itself (maybe it needs replacement) or maybe something else. The issue: the backlight on some of the FN keys is dimmer compared to the rest of the keyboard, or the FN keys next to them. But here’s the tricky part. It’s only one in two keys that has this issue. Basically, keys ESC, F2, F4, F6, F8, F10, F12 have a dimmer light. Whereas the rest of them (F1, F3, F5, F7, F9, F11, POWER, along with the rest of the keyboard), have a normal light. There is no functionality issue with these keys. They all react properly. It’s just the backlight that’s weird. Any idea what could cause this? I’ve never seen this issue before. I was hoping maybe one of you guys had. Also, for as far as I could see on the internet, the liquid damage affects the keyboard in a different way. The keys in the middle of the keyboard light up more than the rest of them. It’s not one every two keys. And only the function keys. The laptop is not new, is not under warranty. And to my knowledge, it has no liquid damage. Here’s a picture of the issue.

Update (12/15/2016) Fixed by readjusting the backlight flex cable connector into its socket. Yeah, that easy. Case closed.

Order a new keyboard backlight, this is the individual part which lights up behind the keys. Chances are, a couple of LEDs have failed, or the backlight sheets are messed up, probably from minor liquid damage directly onto the keyboard. Make sure you order an original new (or used) backlight, with the silver backing. A lot of places sell copy backlights (with white backing) which will have uneven lighting also. After trying a backlight, test it to make sure it is fine before completely reassembling it. Could be gunk behind the keys, so might be worth popping a dim key off carefully and checking.

Exact same problem and fix. Likely common issue as the backlight flex cable is too long and bent in a way that causes a lifting force on one side of the connector. Mine was tilted at probably 20 degree angle when I pulled the back cover off. Here is a pic

One thing to note on failure is every other function key will be extra brighter than rest of the non dim backlight keys. Connection failure probably gave this rail the power of the dim function key rails.