I recently bought a pre-owned rx550 from Amazon to put in my Dell Inspiron 620. It runs perfectly fine without the gpu but when I put it in, nothing would show up on the monitor, not even BIOS. When I bought it one of my worries was not having a power supply sufficient enough as the Inspiron only had a 300w model. So I bought a 450w psu and rewired the system. Once again it ran fine without the gpu but when I put it in nothing would show. The fans turn on the gpu as well.