No picture even after screen replacement

Hi,

I've got a S6 Edge for repair. It is only a tiny line on the glass, but the owner want to replace the screen because there is no picture on the LCD. The phone starts with startup-sound and notification sounds, and the LED in the corner are working.

But after replacement, there is still no picture. It is an expensive, high quality part, tested three times before shipping from the supplier.

Anyone that knows what could be the problem? Or know where the fuse for the LCD is located, so I can measure it and eventually replace it?

I have a good microscope and tools, and have great soldering-skills, so if anyone know about any weak component that may need replacement on the mainboard, I'm likely comfortable with the work.

Thanks in advance!