How 3DR power module fried my APM (and also crashed my drone)

Another crash.. this time thanks to the 3DR power module. I used to have an external UBEC to power my APM and it was actually working pretty well. But 2 weeks ago I decided to get a 3DR power module to make things even better and have a all-in-one product that I believed would improve my experience. Well... today the 3DR power module decided to shut down while I was flying with my X8 quadcopter fully loaded with brushless gimbal and my Sony PJ660. Falling like a rock from 20m high, you can imagine the damages... the camera is BROKEN, 2 arms 2 props and the landing gear... total over 1000$ !!! Then I get back home, trying to cool down and willing to understand what really happened, so I connected my APM to my computer and guess what... THE APM IS BRICKED ! Can't connect it over USB - not recognized. The "ALIVE" led is red and the A led, after calibration, goes into flashing as if it was waiting to be armed. The RC is not recognized either. I have it plugged on my USB port for like an hour trying to figure out how I can get into it, and the APM is hot as hell !!! Almost got burned... yeah it's a bad day for me... 

How do I know it's the 3DR power module ? The little white smoke coming out of it when I went to pick up the rest of my drone on the floor (yeah I used a shovel...). Just for the record, I had 2 4S 5000 mAh plugged into the power module. 

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I wouldn't be so hasty blaming the PM. A short after the crash could have subsequently blown the PM up.
Can you post your log?

Unfortunately the APM is bricked so I cannot access it over USB. Unless you know another method to download them... but thanks for your reply.

Honestly that is the only thing that can explain the crash. The octocopter just shut down in the air for no reason (I had about 60% battery left) and the power module is fried and had white smoke coming out of it until I unplugged the batteries.

You could have exceed the max amps that can be drawn for the current sensor after the crash. You may have exceeded them before the crash with an octo. It's very hard to say what went wrong without further information. Do you know what current you normally draw on your rig? Do you have telemetry from a previous flight with the PM attached, or even without?
A picture of your setup could also help.

What kinda gimbal are you using? How was it powered?

One thing I've learned from experience is to never fly without a ground control station, just to have the logs in case of a total loss.

You don't specify motors and propellers uses, or the weight of your system. But judging by what your have described it sounds like something one the large and heavy side. In that case I suspect you where pushing the PM to hard. The PM is rated at 90A max. 90A divided over eight motors is just 11A for each motor (about 180W using 4S).

Quick note,  I run from  2-4 batteries in parallel on my y6 that is theoretically capable of pulling 150 amps.  I wired my current sensor coming from just one battery prior to the parallel circuit connection to get around the 90amp limit.  I just times all the numbers by 2 or 4 when analyzing draw and the voltage alarms still all seem good.   Anyone know of a downside to all of this?

And sorry for your crash.

I have set up some large multirotors the same way and haven't had an issue.

Thanks guys for your answers. My setup was pulling clearly more than 90A and that is what has fried my PM. Nothing to do with the PM itself, just another lesson learned (the hard way). 

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