please help,
I use Arduino Uno R3 to drive two mg996r servo motors which will move simultaneously. After approximately 1 hour of use, the Atmega16U2 module on the Arduino board caught fire as in the following picture, if anyone understands the problem, I ask for help.
For the scheme, perhaps I can only provide a rough schematic, because I immediately installed the Arduino without making a detailed schematic. My intention was to just try to run the servo, so i just do it without preparation.
from the given information it is hard to tell the real reason.
Did you power the servos from the arduino-Uno 5V pin?
This is a bad idea because such servos draw more current than the onboard-voltage-regulator can deliver.
I estimate that you had an accidently shortcut on the lower side of the arduino-Uno PCB or some small conductant piece of metal dropped on the upperside and caused a shortcut.
What did you use as powersupply and where was the power-supply connected to?
You should describe in much more details how your setup was and you should post a schematic how you had things wired together.
I would to say this different - the overcurrent caused by servos was unlikely to be the cause of the chip explosion.
Although I don't know what OP meant by this
I see, i think this is the problem. Thank you for the info and suggestions. Maybe I'll try again tomorrow by using an external power supply for the servo.
once again, thank you, this really helped me a lot
My theory is:
The load was too big for the linear voltage regulator. There is a lot of power dissipation, as 7V are dropped inside. The cooling is poor and Chinese often use the cheapest components, maybe without internal temperature monitoring. When such a part dies, it becomes a short circuit. So the 12V came directly to the two chips (Arduino and USB interface). The solution is either a separate supply for the motors or (I don't know the consumption of the motors) powering with 5V over the USB port with a strong mobile charger. Then the voltage regulator is out of the loop.
Perhaps op can check if the regulator still works...
If there is 12V on 5V pin it very likely died.
It should be taken into account that the exploded chip is not feeding the servos. It is not the chip that controls the servos... so there is little reason to get so hot...
12volt on the DC socket is close to it's absolute maximum, and you can't draw more than 100mA from the Uno pins at that voltage.
If you do (two servos), then the 5volt regulator will overheat, and (hopefully) will shut down.
It will start/reboot again when cooled down, but this thermal cycling takes it's toll.
The 5volt regulator must have given up after an hour, and shorted regulator will put 12volt on the 5volt rail. Resulting in releasing all the magic smoke.
Leo..
In case of killing spikes, only the controller could be damaged. But also the USB chip exploded, which is not connected directly to the motor drivers. So I am pretty shure, that the 5V line got too high voltage. And this can only come from the supply over the voltage regulator
This part is likely correct - and it happened because the regulator was cooked. That it "looks okay" is meaningless, internally it's probably the equivalent of a wire.
Since the device is now worthless, why not apply 12V and see what the regulator puts out? Maybe do it outside, though, so you don't set off the smoke alarms!
