Indication of ups whistling

• The UPS should not make a whistling noise. You can try a reset to see if the issue clears
  1: Disconnect any attached load.
  2: Unplug the UPS from the wall socket.
  3: Disconnect the UPS' internal battery.
  4: Push and hold the "On" button on the UPS for 5 seconds
  5: Reconnect internal battery.
  6: Plug UPS in to known good power source.
  7: Turn UPS on.
  If the unit continues to whistle after the reset it should be replaced. 
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