First thing first replace cmos battery with a new battery and then clear cmos settings via motherboard RTCRST  jumper.
hi sir/madam, i have one dell optipluse 780 in  my work place. now i facing one issue with this pc right now. when i turn on the pc few seconds i gets green signal on the button after few seconds device will reboot then shows orange signal with fault indication number 1. how can solve this issue.
optipluse 780 booting issue