Modem-like noise in my Back-UPS ES 700VA - Model BE700G-GR

[BillP]

Hi all,

I own an ageing (3.5 years, just out of my 3 years warranty) Back-UPS ES (with european plug). Suddenly it stopped working. Additionally:

• It started emitting an annoying sound similar to that of a cricket, or an old-fashioned modem.
• The sound remains if I unplug the load.
• The sound changes to a monotone beep if I unplug the UPS from the wall.
• The LEDs are all off while the sound exists.
• If I press the 'On' button for 5 seconds and then release it, the UPS switches off.
• The problem appears again if I try to turn the UPS on, or if I unplug from the wall and then plug it again. In all the cases, the 'On' LED blinks for some seconds, then it turns off + there is a "switch" click sound + the modem-like sound starts again.
• I tried the typical cycle (un-plug loads and from the wall, remove battery, press 'On' for 5 seconds, then insert battery again, turn the UPS on) with no success: The 'On' LED blinks, and then the modem-like sound started again.
• I tried pressing the circuit breaker and also no success.
• The load is now correctly working plugged to the wall, as it was before buying the UPS 3.5 years ago.
• The UPS is not working at any time (i.e.: no power output to the load), except during the few seconds when the 'On' LED is blinking.
• The battery displays >13 V when connected to a voltmeter. However, I am not sure about its capacity: I could not make work any of the car adaptors that I have.

I spent some time looking in the forums for a similar description but did not find any report about the same problem.

Thanks in advance for your support!

Best regards,

Emilio

[Anonymous user · Accepted solution]

This is very interesting!

I have an ancient (20+ years old) Back-UPS product that I have replaced the battery in several times. It still works great. I don't have the model number handy, and it's awkward to get to right now, but starting just a couple of months ago, my UPS started making occasional bursts of modem-like noise, for maybe half a second at a time, multiple times a day. It was so brief, and happened so randomly, that it took me several weeks to figure out it was the UPS that was making the noise at all. One day, I happened to be very close to the UPS when it made the noise, and that's when I figured out where the noise was coming from.

So, I'm sorry I don't have an answer to your question, but I did want to let you know you are not going crazy, and even though it seems to happen under different circumstances to yours, I am experiencing something very similar.

Ken