New BX900R-CN with very loud hum- Help requested

[Anonymous user]

Hi all. I purchased a BX900R-CN UPS today on blowout from a local store. I currently have it plugged in and charging after connecting the battery.

My problem is that the UPS is producing a very distinct, very loud humming noise that I can easily hear 20 ft away from the unit. It is at least 30 decibels.

There are no devices connected to it at present as it is in its initial charging cycle.

The noise is the hum of a transformer, it sounds just like an electrical box or a hair clipper. It is plugged directly into a properly grounded wall socket.

Is this normal for one of these devices? I would hate to return it as I got an amazing price for it, but I already know that I could not tolerate this noise for long as it would be easily audible from my bed.

The serial # is 3B0949X10397. If I return it I cannot get another as this was the last one in-store.

Any help would be greatly appreciated.

Regards,

Fenian

[Anonymous user · Accepted solution]

A few other notes after disconnecting the unit:

1) A very loud hum persists even after unplugging unit from wall, even with the UPS power turned off.

Unit is very warm to the touch and has that "hot" electronics smell that rarely means anything good.

I have unplugged the unit + disconnected the battery for now.

Regards,

Fenian