So my brother asked me to swap his case, and I did. Then it worked, but I put the plugs in for front panels, and it didn't. I tried the GPU and RAM in another system, and it worked. I brought out another system, and tested it with the PSU and it worked. I then put my GPU in, worked, then put in Old HDD, as well as old GPU, and then my system now bootloops, with the CPU fan of even spinning up. Please help!