You mean the mains cable??
If it fits then it will work.
What exactly is the mains cable? I'm talking about the cord that connects the power brick to the wall outlet. The cord from my old laptop does fit, but the only difference is the 3A 125V vs 7A 125V. The one that came with my current laptop says 3A 125V and I just want to make sure I am not using a cord that is too powerful.