You know like the kind used to get PGP encryption keys or TrueCrypt FDE keys?
Am asking because on my gaming PC, I have recently developed a low level humming and buzzing noise that sounds like an electronic static buzzing noise coming out of my PSU of my tower desktop PC.
Late last year when the GTX980 came out I built a completely new gaming machine with all new parts, i7-4790k, water cooled, SSD, and Corsair 850 PSU, etc then a few months later I noticed a distinctive low level buzzing noise that sounded like electronic static coming out of the back of my PSU itself. It was intermittent, and with no solid pattern other than the fact that I noticed more often than not, it would usually typically be completely silent when I first boot up the computer, then after the computer was used for an hour or so, it will gradually start the buzzing noise getting louder until it reached a peak. This happens even when I just idle the machine or surf the web, nothing with me loading the CPU too hard or playing games etc. After a few more hours, sometimes the sound goes away, then only to come back later. This is not 'coil whine' and it is not the fan hitting anything or the bearings wearing out. This is distinctively an electronic sort of buzz.
As this progressed I noticed that it would happen sooner. Eventually it got to the point that it would only be silent for the first five minutes, then after that shortly after bootup it will start manifesting that noise again. Basically I was hoping over time it might go away on its own but it was getting worse and becoming more quick to occur after starting up the PC.
I thought about everything from the PSU fan needing to get more lube, to some capacitor going bad, etc... Eventually I just got feed up and went out and purchased another brand new PSU (AX860) to replace the Corsair 850 and immediately after swapping the PSU the noise was gone for good and never came back again. So I attributed it to the PSU and never gave it another thought.
Now, less than a few months after that, I recently started to notice the same buzzing noise coming back, this time on my new PSU! This can't be a coincidence. I don't operate in a dusty environment it is very cool, clean, this can't be something to do with a broken fan or needing more lube. I don't have any performance issues with the computer, specs and benchmarks are as they always were. I am not infected with a virus, (that I know of) to be sure I even low level reformatted my computer, got a new SSD to make sure there wasn't a firmware infection, and switched to a new BIOS (my motherboard has a switch that flips to a backup/dual bios) to make sure my motherboard wasn't somehow compromised.
I can't imagine why. I'm using a quality Monster surge protector and also running an APC Line-R rated at 1200+ though that protector; I am feeding it the best quality power possible.
I'm not sure what affects this has long term on physical use and performance, if any, but the sound is annoying and buzzing is bothering me. I built an otherwise very quiet system and this is irritating.
Anyone else encounter this? Do you think I could be potential victim of some sort of electric grid or power analysis attack?