Keyboard backlight no longer working

[RadicalxEdward]

I just replaced my cd drive with a SSD and replaced my hard drive. During the process I took the keyboard backlight out to fix some of the color sheets i had added a long time ago to make the backlight rainbow colored. I tested the led's before reinstalling the backlight sheet to make sure everything was working. I also wore a grounded anti-static strap the entire time i was working on the computer.

After realizing it didn't work on the next boot, I took it apart and replaced with another sheet from the original keyboard (which I had replaced a couple years ago). booted, and found that one didn't work either. I retested the LED's from the newer sheet and 2 were dead. (which might stop the whole line from working, idk.) I haven't tested the ones that are installed because i don't want to take the computer apart again unless it's going to fix something.

Computer:
Macbook Pro Late 2011 (A1286)
OS X 10.11.2

Repair attempts:

1. Tried replacing backlight sheet
2. reset pram
3. reset smc
4. reinstalled OS

Extra info:

1. If In the keyboard sys pref pane, there is still an option to dim backlight. enabling or disabling makes no difference.
2. light levels make no difference, same problem in dark as light.
3. F5/F6 keys respond and raise bars on screen, but backlight doesn't light up.
4. tried plugging in sheet on outside, no help.
5. cable is firmly connected and all the way in.

Is there any way to test the connector itself so I know whether I should buy another replacement keyboard (first one died for different reason).