Here at work I recently replaced all of our desktop UPSes, about 30 of them. I replaced them with a mixture of APC BackUPS ES 550 and 650 UPSes. So far, I've found seven infant mortalities, including at least two DOAs. (I'm testing them straight out of the box now.) Sadly, everything seems to be okay, except it just won't hold a computer's load at all.

I would suggest that if any of you have one of these that you test it before you need it.

The symptoms I've seen, other than the failure to hold a load of any size include: incandescent lights powered by the battery run at about 75% luminosity (by eye), fluorescent lights flicker on and off, a desk fan's speed drops to about 25%, and apcupsd reports zero load. (Oh, and despite the fact that they're all supporting the same model of computer, the reported loads on the ones that do work right vary widely, from 23% to 82%.)