I replaced my PS last night and I had a problem at first but re-inserted the plugs and it worked fine. My father unpluged the computer from the back this morning. Did not shut it down properly. Since then when I switch the switch on the PS my computer boots up but doesn't work properly. No monitor. Last night what I did was switch the switch and push the power button on the front, worked fine. What could be the problem? New PS ,could it have gone bad over night? I replaced my old one due to bad functionality and high pitched noise. This PS I only hear a very very faint noise and the fan is very quiet. So has anyone else had this problem? Do you have a solution or idea? Please reply. Thanks, Tim

The power supply is 300W.
Mercury.
AMSelectronics.com

this is jsut an idea but the only thing i think of is ur hardrive is screwed, but i cant say for sure, try reseting your cmos