static from all 4 speakers after install

Hi, I just installed a jensen cd player that i just took out of another car. The cd player previously worked fine with absolutley no problems. Today I installed the deck in a 94 corolla and when i turn the head unit on, i only get faint static from all 4 speakers (with a cd or the radio). The head unit seems to be working fine besides no sound. I used a wiring harness and connected the wires with blue butt splices. I double checked all of the connections. I put the stock cd player back in the corolla and it works fine. I've installed one car stereo before so i know a little about car audio. Could this be some type of problem with the ground? The ground wire(black) comes out of the headunit and into the wire harness. I though that grounds usually attatched to the car somewhere. Well any help or suggestions would be greatly appreciated. One more odd thing i noticed, i cut the ground wire and hooked the stereo back up and it doesn't have power anymore. When i reconnect the ground wire it has power. I am positive that this wire (black) should be the ground wire.

The problem ended up being a bad head unit. I got a different one and had no problem setting it up. Thanks for the help.