Hi, recently my MacBook fails to boot into the OS. I have replaced my HDD with an SSD and tried it with other macs and it has worked so when I put the SSD into my mac. The apple loading bar gets to 75% of completion on the bar then everything disappears and there is just a grey screen and after a while the mac reboots. I have tried resetting VRAM and internet recovery mode etc. Also, have tried apple hardware tests and nothing came up. I was wondering is it a GPU issue? I have tried all those fixes for the GPU issue and nothing has worked so im thinking it might not be a GPU issue but it also could be. If it is a GPU issue how i could i fix it? It is definitely not an SSD/HDD problem. Any help would be massively appreciated!