Constant green light with noise UPS APC ES 550

[Anonymous user]

Hi there,

I'm very old customer of APC UPS, having already about 4 different units. Here is the story of a very old version (over 10 years) of UPS APC ES 550 which was not used for years.

Battery is clearly dead and removed from Unit. I could use the UPS as surge only (only 4 outlets) without starting the UPS (not pressing the power button).
On pressing the power button, i could use all outlets, but having the annoying noise and flashing led red. (perfect normal at this point)

So, i disabled the beep noise using PowerChute software, wanted to use ALL 8 outlets as surge protection only (or simple power multiplier). Unfortunately when reconnecting the unit on other power outlet, i got immediately the strange sound and constant green led on power button.

Really frustrating, a working unit (with that limitation on 4 outlets and no battery) after using PowerChute software to turn off beeping sound .. is now having a constant noise. Is basically unusable with such noise, although the 4 surge only outlets are still working.

I notice similar situation at https://forums.apc.com/spaces/4/back-ups-surge-protectors/forums/general/11527/constant-green-light-... (there is no outcome there)

May i know if this unit can still be used as power surge only ? Or at least simple power outlet multiplier. Can this noise be electrically (hardware) stopped ?

Trying to use PowerChute software doesn't work anymore, USB connection ( / or Unit) is not anymore recognized.
I also tried "Reset the unit" but no luck (not sure if procedure was correct executed)

Thank you!

Radu