I've been using this APC surge protector for more than a year. Just the start of this month, I noticed a shrill high-pitched sound coming from inside the surge protector. It's not loud enough to be considered distracting. When my AC is on, it's barely discernible. But when everything is quiet, that's when you can hear it.
This is my first surge protector, so I'm curious to know if the sound is normal? Or should I replace it ASAP?
Have your recently connected any new devices to the power strip?
By new I mean either an additional device or a replacement device requiring more power.
Do you have lots of power outages/brownouts and/or power surges?
If the surge protector has worked well without a previous whine (shrill high-pitched sound) then my thought is that the surge protector has been damaged. Surge protectors can only absorb so much energy before becoming useless.
Start with the following link to learn more about what may be happening.
I do not recommend trying to make a repair. If the surge protector is still under warranty then return for a replacement.
If not under warranty then you may need to purchase a new surge protector. Especially if the current, whining surge protector has been subject to on-going power fluctuations.