UPS ES 750 makes annoying noise.

[Anonymous user]

Kind of like a buzzing sound, it wasn't there before and it's getting on my nerves. It makes the sound even if I turn the UPS off, it only stops when I unplug it. What gives?

[Anonymous user · Accepted solution]

Hi John,

Do you have software to monitor the UPS to see such as load bar on it? How much is recorded? Does it happen when it has load or no load attached to it?

I would suggest you to turn off the UPS, unplug from the wall then disconnect the battery for 5 sec, reconnect it then plug it in then turn it back on. See if the noise will still persist, with and without load attached.