Humming sound when plugging pc speakers and no sound

Good day computer guys, I hope someone can help me with a problem. I have a gigabyte motherboard MA55SLI that was working find until I switch it out and place it in another case. I have tried everything from putting tape on top of the spacer between the motherboard.

I am having a humming sound coming out of the pc speakers before I plug them in. Also no sound coming out of the speakers but the speakers work on other computers. Does any one knows what could be causing this problem.

My guess - you have amplified speakers, which are plugged into the wall to power the amplifier, but input cables are not yet plugged into the MOBO's audio ports...

Several possibilities here, all predicated on the fact that when you say "the speakers work on other computers", they are being tested in another room/building, on 'another computer'... If the wall plug is in the same room, in the same building, I'm with zipzoom in suspecting the bong!

1. You have a crappy/nonexistent ground in the wall plug you're using; four dollar outlet tester available at any 'big box' hardware store will check this...
2. There is something else on the circuit (and it doesn't have to be in the room - many buildings are wired with circuits extending to two/several rooms) that is electrically 'noisy'; suspects are (test by unplugging/unscrewing/removing): anything with a motor - fan, space heater, etc.; a bad or just 'peculiar' CFL (compact flourescent light) - some of the 'cheapies' made in China, Malaysia, et al are incredibly crude; a defective or cheap wall transformer for some random POC that, like every other damned thing these days, was designed too poorly to have an internal power supply; a light dimmer/ceiling fan speed controllerwhose rectifier filtering is 'leaky'...

Save a hit for me!

...but he says he has the hum before he 'plugs it in'...

I am thinking there is a short in the motherboard. If I am holding the speaker cable anywhere close the case that's when I get the humming sound. Once plug in the sound is gone. The correct driver is installed because all players show progress on digital equalizer bars and no system errors. Thanks for your quick response.