Unknown UPS error

[alex25]

Hello,

Simple question here. I've never encountered this error message before, and after thoroughly reading the manual I couldn't find the solution there either.

My UPS (T1000) stopped starting one morning last week and just quickly flashes these two LEDs as an error message. It is fully charged.

In case the attached image doesn't come through, the two lights which quickly flash once are the:
1. Output load level LED - Amber, medium load
2. Battery charge LED - Amber, medium energy remaining

Does anyone have any experience with this? It won't start at all, it just quickly flashes the LEDs. Next thing to try is replacing the battery but I was hoping to get some feedback here first. Thanks, Alex.