I do understand that it is something that you don't particularly want to do when we are nmot 100% sure that is the problem. You could of course RMA the other one if it is still under warranty. The Corsair ones have a five to seven year warranty on them and there are a few others that carry a three years plus coverage. The only trouble with going down this route is that you are without your system until it is returned. I would bite the bullet, buy a new top end one and then send the other for repair and keep as a spare later on. I would recommend a make like Corsair, Seasonic, CWT, Thermaltake, Enermax, Gigabyte, Coolermaster, Antec as they are all good reliable units.