, very loud, high pitched tone which would normally mean that the unit is on battery power - but my computer and everything else connected to the UPS (battery and surge only side) were completely dead the instant the lights flickered the first time

The replacement lasted 3 weeks and was sounding a loud tone and had shut down last night.

The UPS worked fine but the tone was worrisome

I don't know if this is considered normal or not but this UPS makes a constant, loud, high pitched tone

The green light no longer stays solid, it blinks green for a handful of moments and then turns off emitting the very loud tone until I mute it

and this thing woke up in fault mode (solid tone) and wouldn't come back

One shut down and started a constant loud tone within 3 days of using.

The battery sets off intermittent tones requiring a reset or turning it off and then on again.

Worked for a week until laser printer in same wall outlet (not the UPS, baaad thing to do) went off, went into constant overload state, constant annoying tone, can't reset, online help from APC TERRIBLE.

Right outside the return window which is a month it already messed up and keeps producing a solid tone that it’s overloaded when there’s nothing even plugged in!

With nothing but my computer and monitor connected (no speakers, modem, router, etc.) to battery backup, the battery becomes 'overloaded' (generating an ear-splitting constant tone, which CANNOT be disabled) while running any game with even minor 3-D rendering

Not sure what happened, just started constant tone and refused to reset even with all loads removed

It does not work -- I have taken t o the cleaner

t has been working for a few months without any probems