5V to servos from Pixhawk Power Module?

[Aeracoop]

Thanks! Now is cristal clear that we should use BEC.

So, I bought the BEC and wired, but the servo is not working (I checked and Mission planner is showing the changes in Output 7) I show this picture that shows the wiring:

Then, I read here that I should also wire the negative of the BEC to the negative (DC return) of Pixhawk:

Servos not working with Pixhawk

@kamad, There needs to be a ground (dc return) connection between the BEC negative terminal and the negative (-) terminal on the Pixhawk servo output bus. Regards, TCIII GM

(By the way, I’m connecting the BEC to the balance cable of one batery, because I have two 6S bateries in serial)

Then, I made this wiring and some smoke started to came out from the servo

Should I made this wiring between negative of BEC and negative of Out Bus of pixhawk?
Why the servo is not working?

Thank you so much, I appreciate your feedback.

Regards.