Question Static/Buzzing in headphones and mic. Moving mouse creates separate noise.

Sep 4, 2020
I've had this issue before, and was told to get a new motherboard or sound card. I was afraid the sound card wouldn't fix the issue, so I got a whole new motherboard. Now the issue is happening again, and I'm completely lost as to why. I'll explain the issue in more detail:

I got my previous motherboard installed around July 25th. It worked fine up until September when one day I heard a few short static sounds. I thought nothing of it, and it was fine for the rest of the day. The next day after about 2 hours of usage, I heard more of a buzzing noise. I thought maybe a program was running or maybe something wasn't connected correctly. So, I turned my PC off and checked everything. It seemed to be good, so I kept using it, only to get static once again. By the next day, the static was louder and my mouse began to make a noise when I moved it. September 4th is when it started to be its worst (so, about 3-4 days after it started) and I made a forum post. Finally, the next day, my mouse was skipping so bad that I could barely move it across my screen without 5 large swipes. Of course, the static persisted even then. The only useful info I got from that experience is that whenever I touch my case, the static becomes quieter, like the electricity has somewhere to go. The more surface area of myself (idk how to word that) that I put onto my PC, the quieter it was. Also, removing my headphone cables from the jack too much caused a blue screen of death.
Now, with a new motherboard, the same one unfortunately, the issue is starting again. 2 days ago, I heard a few short static sounds like previously. This time, I became scared that the issue would happen again. No noise happened for maybe an hour, then I heard my first quiet buzz/muffled static sound. Saddened because of what happened last time, I turned my pc off for the rest of the day and tried the next day. Literally no noise happened whatsoever for the entire day, until it started again after about 10 hours of being on. Again, I turned it off and here I am today, frantically trying to find a solution before it gets worse. I've only heard a couple of long buzzes, I turned my PC off immediately after they happened, and now I am hearing the short static sounds maybe once a minute or so. Yes, touching my case once again makes the long buzzes quieter. I got this motherboard on the 16th of September, and I have used it daily since then. Which means, like the previous motherboard, this issue is happening after about a month and maybe a week of use.
Extra info/Points I think are worth mentioning:
- I have heard it could be a 'ground loop' or a 'grounding issue', but I'm not sure what those terms mean at all, and anything I read about it goes over my head. - I had a prebuilt using this same outlet for two years without issue. - My case has pre-installed standoffs, and is missing one slot for the right middle side of my motherboard. There is just no standoff hole in the case there, but I've read that a single missing standoff shouldn't be an issue. - My PC is on the ground, but it's not carpet. Plus, I had my prebuilt in the same spot and had no issues even once for two years. - My headphones have a split adapter, but the static persists even without the splitter, and I have tried another pair of headphones. I've tested both the case ports and the ones on my motherboard. Also, the issue happens no matter if I use the case USB ports, or any other USB ports on the back for my mouse. - I'm not getting any prolonged static noise as of now so I cannot test this, but I'm fairly certain that touching the back panel towards the power supply location made the static the quietest. Could it be a PSU issue? - Unfortunately, my front panel connectors were inserted into the motherboard wrong so I have no power button LED, could that have caused the issue in any way? I've been too lazy to fix them. - I have to use a WiFi adapter with this motherboard, but I didn't think that could cause this issue. -

I know this is a long post, but I wanted to include everything so if any obvious issue is present, it would be seen. Also, the more info, the less questions that have to be asked. My specs are:

GPU: GTX 1070 ti (Never overclocked)
CPU: i5-9600k (Never overclocked)
CPU Cooler: Cooler Master Hyper 212 Evo
RAM: Corsair Vengeance LPX 16 GB (2x8GB) DDR4 300Mhz C15
PSU: EVGA 600BR (80+ bronze rating)
Motherboard: GIGABYTE Z390 UD
Case: Phanteks Eclipse P300A