how much silver are you seeing?
mine doesn't seat perfectly, there is maybe 1/8" of the silver showing on my plug in the bottom of the control box. not a lot, but more than i am used to with other electronics.
mine will sometimes be real touchy about how the power cord is seated. i've found it works best when the unit is mounted in such a way that the power cord can hang freely without any sideways pressure on it. sometimes giving it a small twist after plugging it in gets it to turn on.
that's probably my biggest complaint about the unit is that it can be a little touchy with how that power cord plugs in. might be some corrosion on the contacts to, depending on how and where it was mounted. if there is corrosion, some fine grit sand paper carefully applied should be able to clean the contacts off.
