hi all computer wizards; I have strange problem with my UPS I have 500VA UPS ; sometimes when I am using my PC and power goes off my UPS doesnt give continuity; it works like a normal battery; i.e.; something like you switch off power of computer without a UPS; but sometimes it does give continuity .I showed it to hardware repair man but he didnt find anything wrong; because when we test the UPS like we switch of the power manually from the switch board UPS works fine and gives continuity too. I had even tried taking off Monitor off the UPS thinking Monitors power surge could be problem; but nothing. Where is the fault????