Let's Make Robots!

OHNOES I fried something!

Hi guys, 


Sooo, I've fried something, and I'm not sure what it is or how I did it! 

Can anyone enlighten me?

I've stared at the schematic provided by arduino but I can't make sense of it..

Picture of the board below, I've fried the little black component behind the power plug..

Powering the arduino with 9v, drives two servos, and is hooked up to a motor driver with two geared motors powered seperately, the arduino also has the Dagu compound eye hooked up to it. 


Anyone have any clue what I have done wrong/what I have fried and how?! 



Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Yes that looks like the only way to fry that diode. You could solder a bridge to connect the pins of that diode so you bypass it. Just watch out when you connect a power supply that you don't make the same mistake again :)

http://arduino.cc/en/uploads/Main/ArduinoUno_R3_Front.jpg I would say it is a surface mount diode labeled M7 (on the diode body, not on the board.)

I looked at the schematic and D1, up near the power supply section is in fact labeled M7.

I would go way out on a limb and say you reversed your polarity in a big way.

I'm going to have to admit to having done this now...

soldered a bridge and the board's working again, have also labeled my wires, so I am less likely to refry my beans. 

Thanks for solving the mistery though


That is diode D1, this diode is used for reverse voltage protection. Strange that you blew it up :p

I don't get what you mean by "I am not powering the servos through the regulator but am using the 5v the board supplies to power the servos through the 5v output pin"  You do realise that the 5V pins on the Arduino get their 5V from that tiny regulator? That's is the reason you don't power motors or servos from the Arduino 5V pins.


The black component between the power jack and the USB connector? That is component U1 the 5V regulator. Where you powering the servos from the 5V regulator? An Arduino can control a lot of things but NOT power them...

Thanks Bajdi, I actually meant the component to the left of the bottom row of pins (next to RESET and IOREF etc.) 

I am not powering the servos through the regulator but am using the 5v the board supplies to power the servos through the 5v output pin, I was not aware this could cause problems though? 

It can and did, the regulator can't supply much current, motors want current, lots of it.

Interesting, so just double checking, because this does confuse me! 

To clarify, the regulator is still working fine without any issues. 

But if I understand correctly, you are saying that the 5v output pins on the arduino board should not be used for servos, in which case someone needs to tell arduino to stop teaching me lies http://www.arduino.cc/playground/Learning/SingleServoExample