cpu dead?

[cm01]

Hi,

after solving an issue with gps after a crash I now have got a dead mcu. Bad Luck seems to be on my side.

I was connecting 3DR Telemetry to the board and it was working, but at a distance of app. 5m it was loosing connection and regaining connection constantly.
I think I was also disconnecting and connecting gps antenna, because I was looking for gps lock.

Suddenly the board was dead. No power led.
I still have 5 volt, but the 5210 3.3V regulator is very hot and the output is very low. I also have a big voltage drop (> 3V) on R13. The MCU is getting warm as well, so i guess I have a shorted processor.

So my first question:
Is it likely, that the cpu is dead and can it be replaced?
I have read, other people in this forum had replaced the mcu succesfully but I have never soldered a 100pin beast before.
What do i have to do?


My second question:
What could have caused the dead cpu?
When I connect 3DR radio telemtry, do i need a level converter for 3.3V?
(I didnt use on)

Thanks

Chris

[plexus]

Hi,
Sorry for your crash.
The first thing to do is to contact JussiH to see what he can do.
On my AQ , I had a similar problem, 5210 very hot and mcu too. I cutted the track beetween the output of 3.3V and the MCU to see if that was the MCU out. After that, the 3.3V was present. The MCU was out of service. JussiH helped me with a new MCU (thanks to him).To replace is possible but if you are not ready to do that work, becare.
On my side I dont know why the MCU is dead. May be some electricity static....
Now my AQ works very well.
The 3DR radio is powered in 5V by the AQ with jump in place. No converter 3.3V.

[cm01]

Hi plexus,

thanks for reply.
I disconnected 5210 and 3.3V was present.
I am trying to contact Jussi now.

Thanks
Chris