Hi, I have a power problem with my DELL Optiplex 260. I can put on the computer. It starts normally but it couldn't load the operating system. When noticed that, I went into the BIOS and saw : - Primary drive 0 : Unknown device - Primary drive 1 : Unknown device - Secondary Drive 0 : Unknown device - Secondary drive 1 : Unknown device I replaced the IDE cable, the result was the same trouble. I replaced the power supply box but any change has been detected. The power can enter the power supply box but there's no power out. So, if somebody can help me about this issue I would be very happy. Thanks!