I have a MacBook Pro 15" early 2011. It has been slow and full since a long time so I decided to upgrade it with a Samsung 870EVO 2.5 SATA SSD.
Since then, I can't access anything. I can't boot from a USB (tried 3 USB keys and Lion, Sierra and High Sierra) white screen of death when I boot with the USB after the selection of disk. I can no longer access recovery mode (white screen of death after loading).
When I put in the old disk, I get a sign that I can't get through after loading with the logo. I can't access recovery mode either (white screen of death).
I can't type a command in verbose (with old disk) plus it goes into error too.
Do you have any ideas?