Had a problem with glitchy screen, now no backlight

Hi,

my computer had a glitch in the screen: pink lines in white zones and green lines in black zone. A bit like here : Pink lines in white space, green lines in black space?. I opened the computer to see if there was something loose. There was nothing I could see so I closed it and since then the computer starts but there si no backlight (I can see the screen with a flashlight through the apple logo). I've tried the opt+cmd+P+R and it changes nothing. I guess it's hardware since it didn't happen before I opened it.

Is it something I can fix ?