Backlight LEDS not being powered

I have a LG 49UH603V and the screen turned blue. Upon inspection the leds were almost all blue so I ordered a backlight kit to replace them.

I first removed one strip (bottom row, closest to power on button) and replaced it by a new one to check if it was working. It wasn't working but the rest of the old blue leds were turning on. Then I tried to replace the top row to see what was happening but then nothing was turning on.

So I put all the old blue strips back on and still, nothing was lighting up.

All leds (old and new) are working, I tested them.

Then I tried to measure the voltage on the power supply, the led connector on the board gave me (I think) a good reading but the little connectors going into the strips, I couldn't get a normal reading on them.

At this point I think it's useful to inform you that I have no prior knowledge about those things, just a decent sense of logic and access to YouTube. I'm guessing there is an issue with the power supply board but I really have no clue of what the next steps to source the issue should be, would appreciate any help provided :)