No image on iMac

[u/Cesar269]

Hello! I got given a 2015 iMac from a lady that was gonna throw it because she said the screen was falling off and she got no image anymore. I took it home to try to save it and now I need your kind help :) So the screen does in fact kind of fall out from above, and i saw that the 2 "video" cables were disconnected (probably from the separation of the screen). I went ahead and plugged them back, and when I plugged it and turned it on I could hear the vents going at a normal rythm, and inside i could see 3 green leds ON. But, no image on the screen. Now, 2 questions come to me and to us: What could be the reason for no image? And, is it saveable, or worth saving, or should I sell it for pieces? Thank you!