No Backlight After Screen Repair

Hi

Just replaced the LCD on a Macbook Pro 13" Retina Early 2015.

When I it turn on, I can hear the chime but nothing is displayed.

I found out that the backlight didn't turn on.

If I disconnect the LCD cable while the Macbook is turned on and reconnect it, the backlight turns on and the Macbook works like a charm.

Has anyone any idea what I can do to make it work everytime I turn the Macbook on?