I’m going a bit crazy and I don’t know if you all are just living with this, or I have really bad luck. Please help.

I purchased a new CyberPower 1325va UPS (model lx1325gu3) from Microcenter for my PC. It’s sitting on the floor under my desk, and it’s making a faint but noticeable very high pitched noise that is slowly driving me mad. It’s not just me; someone else was able to hear it from the hallway when my door was open.

The noise is a lot quieter than when the UPS battery kicks in, so it’s not that. It’s not the beeping noise it makes when it activates either. It’s just a constant background hissing sound and while it’s very quiet, it’s so high pitched that it’s hard to ignore. Also, when I unplugged everything from the UPS then unplugged it from the wall, it continued to make the noise for a few more minutes before stopping. The closest thing I can compare it to is like having tinnitus. I exchanged it for a second one from Microcenter, thinking I may have just gotten a defective one, but the second one makes the same noise.

Is this normal? Did I just get two bad ones in a row? Is this a common problem with this particular model?