Anyone here ever had a PSU tick/crackle when under really low loads (and it's not the fan)? I have this HX520 that does that unless an HDD is being actively accessed or system load otherwise rises from idle, on a Core i3-6100 box acting as a NAS. I've sort-of-fixed the problem because since this is a home server, I turned off the HDD spindown timeout in Windows, which indirectly solved the problem. I'd still like to gather gerbils' opinions.
I've read somewhere that "switching" power supplies exhibit this problem with really low loads, and I suppose that back in the 2007 age of 8800GTXs and the like, Corsair wasn't ever expecting a computer that would draw so little power.
Yes, the PSU may be old, but it's working okay and I'll probably die before it does. It was powering my main rig before with an i7-6700K (overclocked), and a GTX 970, and five HDDs + 1 SSD, plus a bunch of USB stuff.