Dear Community, I'm very desperate now. I bought a cheap Mac Pro 3.1 some time ago and am currently upgrading. To the initial situation and the hardware: MacPro 3.1 with 2x2.8 Quad Xeon - With a 2600XT I upgraded to High Sierra with Dosdude Tool, installed 32 GB RAM, moved the SSD to a PCIe card and installed 32 GB Ram. I exchanged the graphics card for a flashed 8800GT. Now I wanted to install a RX580. For the power supply I use this cable: https://www.amazon.de/gp/product/B07GPBRWDX/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1 When I start up, the card goes on / the fan starts running fast, but becomes quiet again. So far so good but I only get a white BIld (or a grey one? It already looks like it's showing something), but nothing more. Remote access from another Mac doesn't work. Does anyone have an idea?