What if a USB was plugged in backwards, what would happen, and would Windows warn you?

USB is keyed so that it can only be plugged into a port a certain way, to ensure that the contacts touch. But what if you either forced it to plug in improperly, or the port itself was worn down and the plug was worn down and you could plug it in backwards? What kind of havoc, if any, would it cause?

Solution 1:

It just wouldn't work.

The contacts are only one one side of the socket/plug so putting the plug in the wrong way round will mean that no connection will be made.

You'll also potentially damage the plug and/or socket so it can't be used again.

I should just add (to answer the final part of the question) that Windows wouldn't warn you because it would have no way of knowing that anything had happened.

Solution 2:

PQI has a habit removing the outer metal from the USB connector on their USB drives like the one I have above.

It's just as easy to put in "backwards", but as others have pointed out, it simply does not make contact with anything. Thank goodness there's a light on it, so it's easy to tell when I've put it in the right way ;)

Solution 3:

Nothing. It's not symmetrical. No contact would be made.

Solution 4:

Well the electrical connections would not match up, so I think the worst case would be a short which would likely damage the interface circuitry on the mobo. I doubt it's designed to handle that, because the connectors are keyed. Other than that I think it would be limited to the physical damage to the connectors i.e. they wouldn't work any more.

How persistent did you have to be to get that connector in backwards?