1000W PSU should be more than enough unless you have something huge you are trying to power even a GTX 1080SLI GPU only requires you to have a 900W PSU. I think you may have a short somewhere on the motherboard by the south gate. It could be a micro-soldering repair. Or you may need to buy a new motherboard. You can test my theory by using an alternate motherboard (if you have one lying around). Plug everything, into the alternate motherboard, that you were attempting to plug into the motherboard in question. If it works then the problem is definitely a short on the motherboard and you should repair or replace the motherboard.