I have a 2nd hand bought Dell GX620 desktop which failed to remember it's bios settings once the power cable is removed from the psu or there is power cut from the public power supply. I have changed the cmos battery from another desktop Optiplex GX 745 that works yet the problem remains. Some of the discovery I made include a dead power indicator lamp, but the system still boot, and none existing jumper on RTC reset pin. I remove the Pswd jumper for the RTC reset pin, restart the system, reset time, date and others save the settings and reboot the system. The system will boot into windows without any error message as long as the power cable remains in the psu. Once the power cable is removed from the psu even for as short as 5 seconds, settings are lost whenever I restart the system. I have read similar posts on the same type of Dell desktop and follow the steps or suggestions which have not yielded the expected result. It is the removal and replacement of capacitors is what I have not done as there is no bulging capacitor on the mobo. What else can be done to solve this problem. Thanks