MacBook Pro 13'' early 2011 Keyboard Lights wont light up

I would like to rejuvenate my Mac Book Pro 2011 that had some issues (screen loose, overheating, keyboard lights not working)

I had no problems for the 2 first tasks, but the lights still not working.

I've reset reset the PRAM, but nothing

I've ordered a new set of lights and replaced the old one and... nothing.

At this point I've tested each single led and they are woking fine (also in the old set).

As last attempt i've tested the computer board and check that the connector status. As in the photo you can see that there is a voltage between the left and right side of the connector.

I've also changed the intensity using f5 and f6 and the voltage was different.

Any one have an other idea?