pic: Well there's your problem...

[Mike Betts]

Jared,

Actually, what you see could very well be the result of the failure and not the root cause...

When a power semiconductor fails, it almost always causes a resultant short circuit. This has to do with the inner structure of the device. The actual cause of the failure could be a voltage spike, over-current, loss of cooling (over-temperature), et cetera.

As an example: An over-current condition can be the result of a logic failure upstream of the device causing a "shoot-through" condition (the upper and lower halves of a power pole turn on simultaneously shorting the 12V to ground). This logic failure could be caused by a piece of aluminum dust shorting out two pins on an IC chip elsewhere on the board.

So when you see power devices failed like this, think of it as an indicator that something else failed...

Of course, the failure could indicate a manufacturing defect or a design deficiency as well...

I hope this makes things a little more cloudy for you... Welcome my world...

Regards,

Mike