Hey guys, just came back from the apple store because my MacBook Pro 15 retina from 2012 have screen/GPU problems. The screen goes black when I edit on Lightroom or read a 4K video or something that requires some power. I also have no light on the Apple logo in the back of the screen and no signal on HDMI or mini DVI. The technicien at the apple store think it’s from the screen, an alimentation problème when the computer over heat. Apparently everything is connected and when the screen goes black it also cut off every video Chanel so HDMI and mini DVI also. This happen since I’ve installed Catalina, I was able to downgrade to HighSierra with a usb bootable but the problem is still here when the computer over heat. I was wondering if you guys have any confirmation that when the screen goes black it also cut off the video on hdmi ? Apple is charging me 680€ for changing the screen or the motherboard/GPU. I’m trying to change the screen myself if it’s that. But I don’t know..