In January I bought Seasonic 860W 80Plus Platinum. I read review about it and considering Seasonic's reputation I took it. My excitement didn't last long. The moment I switched to ON it instantly starts emitting barely noticeable high pitch noise. But it wasn't something to brag about, since it was silent in closed case. It was still silent during POST and booting. But after system booted into OS, it starts emitting loud high pitch noise. And because I received it on Friday, I had to keep it the whole weekend. During those two days not only it was driving me crazy, but I also started having headache. A terrible one. So, the first thing in Monday morning I went to shop. I was told they will order replacement, but as it turned out they send PSU for warranty repair. I have waited for almost a month, only to discover that repair technician wrote it doesn't emit such noise. Imagine my frustration... Anyway, since I didn't have spare time to test it, I let it in the box for another two months. I finally got time (and nerves) to take the PSU to another PC, with older and totally different configuration. The same noise appeared once again. Confident that the PSU IS faulty I let it few days in a box, so I could send it back again. Two days ago I needed to test something, so I plugged it back. And then I heard it: SILENCE! It was miracle! I was happy beyond words. I was even afraid to turn the PC off. The next in the morning it was still silent, until I fired up Left 4 Dead 2. The noise was unfortunately back and didn't stop. And this is what troubles me: the inconsistent behavior, which makes my warranty repair difficult. Why it was suddenly silent? Why it returns back after playing game, when yesterday it was fine? And why on earth it's emitting noise only in OS and not the whole time? I spent 190€ for the PSU and I don't have such amount of money to buy a new one in case they refuse to acknowledge the issue. How should I proceed? I was thinking to write about this behavior and test in different PC. Will be this enough?