I ordered a replacement control box for my microwave.

When it arrived today, I was pleased to see that the front of the box does, indeed, look exactly like the old box. However, there is one connection in the new box which is different from the one in my old box: it's a 3-pin instead of a 4-pin.

I'm told that the part was not redesigned, but it clearly is different and cannot possibly be attached. The new part number is DE94-01807A.

I suspect that it would do no good to order another control box -- it would probably be the same, wouldn't it?

What could be the problem?