You should check the batteries to see if either or both are dead. A good 12 volt battery should read 12.6v DC. If the battery voltage is to low the UPS will not power on.
Thanks, but this was plugged in but turned off for the week I was gone.
I expect it is something different than a dead battery.
This was purchased May 2020, so less than a year old.
However, I will do as you suggest.
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