Hello people,
I've made a little buzzer system with my Arduino Uno few weeks ago, and it worked fine, until the day that i needed it, when i turned it on, and tested a little on the buzzer and poof, it died, and when i try to upload the blink sketch to see whether the board is still working, the programmer not responding problem showed up.
Prior to that, while I was testing the buzzers, one of the transistors burnt out of nowhere, and then when i did the upload, it failed, so I suspect that it has something to do with the transistor. Can anybody please help me troubleshoot this?
This is the circuit diagram showing how the transistor was connected.

Thanks.
