Just the title. I was working on upgrading a Dell Inspiron 3847 my dad never used, accidentally got the wrong size graphics card and just moved everything to a new tower. I plug my PC in and try powering it on but get no dice. The PSU is working, (I took it out and tested it) and the 24-pin connector is fitted snugly. I tried the old power supply as well and get no result. I am not at all sure what could be wrong. My parts didn't all come in at once, and I was away for several weeks before resuming the build. Could my motherboard be the problem?