Chosen Solution

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?

I cannot be sure of what your are measuring with your multimeter, but the backlight connector has 4 pins, 1 connects to Smc, one to ground, and two probably to u5850 where power comes from..you didn’t mention your board reference. If you get the right figures from u5850 you have a problem with Smc or an open/shorted line between it and the connector. Hard to say without testing what is faulty for sure.