Just got an RMA replacement for a HX750, a HX750i. All installed and booted fine. Then I tried gaming, and noticed a buzzing. Stopped the game, buzzing had stopped. Tried Unigine, and buzzing starts as soon as the bench starts. If I stick my ear by the back of the PSU, I can hear buzzing while the system is at idle too, but it's much quieter. If I move the unigine window about, the buzzing stops when the window is moving (bench is paused), and starts as soon as the window is released. If I run prime95 to stress just the CPU, there isn't any increase in the buzzing. If I run Unigine on very low settings to reduce power draw as much as possible, the buzzing is still there. It's definitely coming from the PSU and not the graphics card, and there wasn't any noise like this before (old PSU was RMA'd due to noisy fan), so my conclusion is dodgy PSU even though it only really buzzes under graphical load. Sound like the right sort of conclusion? Video of buzzing, load starts at 15 seconds.
It could be the fan catching on the frame although it's difficult to tell from the video but it doesn't sound like normal coil whine. You could try loosening the fan screws around a 1/4 turn to see if it makes a difference.
Makes the noise when fan isn't spinning, rules that out, . Doesn't sound like other videos of coil whine, it's more of an electrical shorting type of noise. *UPDATE* Switched back to my GTX660, and buzzing still there, so definitely not GPU.
That sounds like coil whine to me, exactly like the noise I get from my old PSU (I replied in the What's Ruining... thread). It won't damage anything as it's a normal occurrence but Corsair should swap that no issue.
