Hi all,
Owner of a S12II 520 watt power supply bought in 2012. For the past six months, the PSU has developed a rapid clicking noise, identical to the audio recorded on this video: https://www.youtube.com/watch?v=3J4WsZ_gfTk
I have confirmed that the noise originates from the PSU because it is still present even when the CPU and case fans are unplugged. It also occurs when the PSU fan is halted.
I don't think it is coil whine because it is much more louder—audible even when standing across the room—and occurs even when the computer is idle. The clicking becomes more rapid when the computer is under a heavier load.
There are various reports from around the web addressing this same issue with both the S12II and M12II:
https://www.eevblog.com/forum/repair...-pc-psu-noise/
http://www.tomshardware.com/answers/...orks-fine.html
https://www.reddit.com/r/techsupport..._a_very_quiet/
There doesn't appear to be a consensus on the cause. The thread at the first link claims it is an issue with the PFC circuit. The others threads fault bad capacitors, which I don't think is true in this case.
Is this a known issue with the S12II and M12II lines? Any insights what is causing it?