Possibly fried an UNO

I’m quite new to Arduino so please bear with me.
So i’m working on this little project, im using four servos connected to one pin, though so far i have installed only two. To make the servos work properly, I connected 12V charger to the round power slot, and two 9V batteries connected to each other to the bread board. That did not work, so i had to connect the power line from the bread board to the Vin port on arduino. I know this is pretty stupid, but I did not realise that the power is more than 20V. The small black rectangle next to the round power slot started heating up rapidly. Now the board works mostly normally, it runs the program it had stored, but I cannot upload anything new on the board.
This is the error code i am getting:

Arduino: 1.8.9 (Windows 10), Board: "Arduino/Genuino Uno"

Sketch uses 930 bytes (2%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0xf9
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xf9
Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Is there anything i can do, or do i have to buy a new one?
Thank you for any help.

Welcome to the forum. Please read 'how to use this forum - please read'.

Yes, you probably fried it, yes you probably need a new one.

When you have read the forum instructions please post a circuit diagram. Some of the things you say in your OP worry me, but without seeing a schematic of what you are doing I can't be sure.

I am having problems with registering to fritzing, so i hope this will do. image

Thank you.

A lot of people here don't like Fritzing, although I'm not too bothered. I suggest a pencil and paper then take a photo of the drawing.

  • You are powering the Uno with 12V into the barrel jack, which is fine.
  • You are also powering at 18V from the Vin pin from the 2 batteries, which is not fine. Disconnect the red wire from the breadboard to Vin.
  • You have the ground from the battery to the Uno ground via the back wire to the breadboard, this is also correct so leave it in.
  • Unfortunately I have no experience with servos, neither the ones you have or any other, so I don't know if the connection is correct or not. I suspect it's OK but I hope someone else will comment here and give a proper answer.

Which black rectangle was heating up? The one with one tab and three large pins? Something else?

Whatever heated up is probably toast.

You cannot have two external power supplies connected to the Uno at once. You say it didn't work when power was connected to the barrel jack - when you say it didn't work, do you mean it didn't power the Arduino at all? Or what?

Which serial interface chip does it use? The official Uno's use a 16u2, which is very easy to fry if the power rails are abused.. If it uses the 16u2 as serial adapter, I would be very surprised if the '328p was damaged. The serial adapter on clone boards (CH340G or CP2102) is much more durable, and can survive things that destroy the '328p.

Fritzing sucks; among other things, since people always use parts that aren't available in fritzing, they substitute other parts, and then the diagram shows something different from what you are doing, leading to confusion among the people trying to help you, as they comment on what the diagram shows instead of what you actually did.

Drawing the connections on a piece of paper and photographing it with your cellphone is better.

Yes, the one with three pins and a tab. I had an original UNO, not a clone. The lights on the board are on, and for a while I could even run already downloaded program, not anymore though. It is for sure not working anymore so I got a new one. Thank you all for help.