2009 bought Back-UPS-ES 450/550G.
It just now all of a sudden started this incredibly loud, maddening, nonstop whistle!!! It's making me very sick!!! In desperation I pressed the little button by the side of the light but it stopped my computer and I lost all the works I was working on!!! PLEASE someone tell me ASAP how to stop it AND tell me WHY this happened?
Thanks very much!
P.S. I hope I'll receive answers to my email as I don't see here where it says "Instant notification".....
Without knowing the root case, the easiest way will be to remove the attached devices from the UPS, then turn it off and remove the UPS from AC power at the wall outlet (so unplug it). if it is still happening, then disconnect the UPS battery and it should cease.
it's hard to say without hearing the noise but maybe the beeper failed?