Orijinal gönderinin sahibi: Reece ,
If the old screen is lighting fine, and the new screen is not (and you have tried plugging in the old screen after, to see if it works), the issue is with the new screen. You can try swapping the LCD cable, but I highly doubt this will resolve the issue, it is likely the screen PCB which is liquid damaged inside the hinge cover. As long as you bought a 2015 A1398 model, there will be no compatibility issues. The cables from 2012-2015 Retina 13" and 15" models are all the same, the difference is the screen panel itself uses a different layout of components, so they require different signals/voltages in different places to the older models. You probably should have just bought a replacement screen, NEVER buy a liquid damaged donor to swap parts from. Liquid very easily gets spilt over the screen, goes into the hinge cover and damages the PCB (or backlight sheets). Your best bet is to just buy a replacement lid assembly, from checking your original question I can see the original screen is just damaged.