Have I fried my Uno with 9v supply?

Development Tools IDE 1.x
1

Hi, I was working on a project where I had a mess of a worktop with wires, power supplies and components lying all over the place.

I mistakenly picked up the wrong power supply and plugged to into my Uno board. A 9v supply.

It was in there for about 30 seconds before I was alerted to a problem by the smell of hot components!

Immediately after this I was unable to load a sketch. I received this error message:

avrdude: verification error, first mismatch at byte 0x0000
0x62 != 0x0c
avrdude: verification error; content mismatch
avrdude: verification error; content mismatch

I was definitely using the correct port and had the correct board selected.

On trying to load the sketch the TX and RX lights flash but the TX light remains on and L remains on.

So, my question is - have I caused irreversible damage to the board?

I have seen some posts suggesting replacing individual damaged components on the board but my technical know-how just isn't up to diagnosing which component it is and how to replace it.

Thanks in advance for any suggestions (even if the suggestion is to buy another board)

2

You left out the most useful piece of information. WHERE exactly was the 9V connected to the Uno...what pins or connector? There are several places where 9V would be no problem.

Steve

3

It was using the DC connector on the Uno board

4

9 volts is the best you can supply to the DC jack. Assuming the center pin is positive.. :slight_smile: If not, you have probably destroyed the voltage regulator and possibly even one (or both) of the electrolytic capacitors. The damage can be even worse of course. I would check the connector polarity first. Do you have a voltmeter?

PS keep in mind that components which have been exposed to conditions that exceed those specified in the datasheet can't be trusted anymore.

5

On trying to load the sketch the TX and RX lights flash but the TX light remains on and L remains on.

So how?