My power LED only lights up when the computer enters sleep mode with my DG45ID motherboard. I've had the motherboard for two years, but until yesterday the case I had been using had the power LED connected directly to the power supply with a molex connector. The new case has both a 2-pin and 3-pin power LED connector like most computer cases do. After installing everything into the new case, I connected the 3-pin connector to the "Alternate Power LED" pins. I plan on trying the 2-pin connector to see if that makes a difference, though I doubt it would since the manual says the same signal is sent to each of these connectors.
Is there a reason why the power LED would be off when the computer is running and come on when the computer enters sleep mode?
I opened the case back up and used the 2-pin power LED connector and it is working correctly. I'd still like to know why the 3-pin "alternate power LED" connector makes the power LED light up opposite of when it should.