Black day cpu dead

[plexus]

Hi,
I dont know how that was possible , the regulator 5210 3.3V seems to be dead.

Before its happen, it was not possible to connect the board to the GCS but the led was blinking.
I hope the MCU is not dead too, the 5210 is very hot quickly and no led now.
Many thanks to you.

[Kisssys]

That doesn't sound good, Pin 1 of the 5210 supply's the 3.3 volts to the processor. You would probably see a large voltage drop across R13 also. The Red led shows that the processor has power.

My bet would be a shorted processor.

I have a pair of tennis shoes that seem to create static, when I put a board into my reflow oven one time I got a shock. Sure enough I blew out the processor and the output of the 5210 was very low.

[plexus]

Yes Jussih,
It is not good because I isolate the pin 1 of the 5210 and the 3.3V is good, so the regulator is not dead . The track going to the micro is grounded (pin19 of the STM is in shortcut to the ground).
To me it is finished, the board is dead.
So long.
But Is it possible to get another STM32F417 for the board ?
See the card without the STM:

stm.JPG (60.58 KiB) Viewed 10581 times

[JussiH]

Unless there is some physical damage to the board, its not a problem to replace the MCU.

I would have offered to examine and replace MCU under warranty, but it seems you are well on your way to do so yourself...Be careful when you clean up the pads with solderwick. Use plenty of flux and go along with the pads.

Is the Mic5210 still shorted after removing the MCU?

MCU is a STM32F417VG - STM32F407VG will work too. (LQFP100, 1MB flash)

[plexus]

Hi JussiH,
Thanks you very much.
The 5210 is good but, may be, it would be good to replace it.
For the MCU that was an STF32F417VGT6. I think that I can solder it without big problem because that is not the first time i do that. Anyway if I had read your message before, I would send to you the card.
Thanks again for your help.I send a MP to you.
.Alain

[JussiH]

Alain, I am sure you understand that reworking the board voids the warranty immediately. I´d like to point out that in case your board dies "for no good reason", you should always contact your reseller or me before beginning rework of the board. We have what I would describe as a "very reasonable" warranty policy on the AQ HW.

I will send you a new MCU in todays post - I am confident that will make your board work again - provided of course you verify that the shorts disappear when MCU is removed.

The symptom you get points to a dead MCU, there are several ways that can happen, please consider if anything of the below could apply to your case :

As Steve says, a large static discharge can kill the processor. However, I have built a lot of these things and it never happened to me.

You should always connect individual ground wires to ESCs and other peripherals to keep them at same potential. I suspect that another very similar case to yours was caused by different ground potential between board and a RX.

If the signal pins on the board is subjected to power above their rating, it will destroy the MCU immediately. I have had to replace MCU on one of my boards on that account.

[plexus]

Yes I understand for the warranty and I thank you a lot to send me a new MCU. I appreciate your help.
The problem was coming when plugging the battery on my hexa. But also an other problem of connection with the QGC just before.
So the MCU is dead, but I am happy to continue very soon with autoquad.

[kinderkram]

Hi Alan,
thx for trying it on your own. But please be careful and make absolutely sure, no other part on the board is damaged before you power the board after the soldering.

Good luck!

Norbert

[plexus]

Hi all,
I got a new STM32 sended by JussiH that morning. After solder it on the board, my AQ seems to work well.
I loaded the firm and parameters and the card work well, motors too.
Now it is time to redo all the calibrations.

Many thanks again to JussiH for his help to sending me a new IMU without charges.

new stm1.JPG (75.39 KiB) Viewed 10408 times

[leopold1]

Plexus, I hope it stays working.
I also had a black day and the board is being investigated by Jussi.
I'm a little bit afraid to hook it all up again and experience the same thing.
Its not an isolated event.