Dell UPS Rack 1920W in USB AC Power Failure

Hi everyone!

we've been using the DELL USV 1920Watt for several months here in our university facility. two weeks ago we experienced a major power failure in the neighbourhood and since then the UPS has just stopped working and it simply seems to be completely dead. Meaning that the device does not turn on and even the front display stays off. We've already tried some things one can think of including taking out the battery or changing the cables. Here is also a screenshot of the Event Log viewer in Dell UPS Management Software:

So any suggestions would be appreciated as what to do next.