This is an extension to my earlier post(http://forums.mydigitallife.net/threads/21202-How-to-test-SMPS?highlight=) on UPS damage to power supply. My PSU first gave off smoke when it it was just connected to UPS during a power outage for about 10mins. The Computer had been already shut down immediately on seeing the power outage. Even the LCD monitor was in standby state. I could see fumes rise out of the power supply. I shut down the UPS. After waiting for 6 hrs I restarted and to my relief comp. started normally. I checked the voltages on all the 3 rail using Intel Hardware monitor software . It showed all voltages to be all right. I was able to extract abt 2 months work from the PSU. Week ago I accidentally left the UPS on (comp was shutdown) again. This time I could not start the Comp as PSU was fried. I have now got the PSU replaced(in warranty) but am now afraid to leave comp on unattended for even a short period of time as I feel if there is an outage in my absence I will lose another PSU. Is this a known problem or is it related to UPS pSU pair that I have ie Microtek 1kva UPS with Coolermaster eXtreme Power Plus 500W (RS-500-PCAR-A3). What can be done to prevent a repeat. I will buy an APC UPS if there is a need.