My reward for clicking the "test" button in the APC UPS software was that it completely cut the power to my SQL server. The server promptly rebooted, the SQL service is running (verified by the app on another server that queries it), but the GUI has remained on "applying computer settings" for 20 minutes and counting, and it forbids RDC connections. Since SQL is up, it is fulfilling its key role, but it's obviously not right.
What step to take next? Wait longer?
Hardware is a Dell Poweredge 2850, internal RAID10.