I am working on my MSc final project with an Arduino BT.
To do so, I was using a set of 2 AA regular rechargeable batteries to power it through the grey socket. Although the board was powering on alright, it was working very very unstable. Very hard to get it connected to the computer and upload sketches (yes, I know I have to pair it and then press the board’s reset button to upload things :).
At the lab, 5V DC to the board made it work better, so while at home I powered the board with 9V, but not through the grey socket, directly to the pin sockets marked 9V. I am sure I have not reversed polarity, but as soon as I put it in, a little smoke came out. I could not spot from which component it was, but now, unsurprisingly, the board will not turn on (LEDs will not light up).
I would hate to have to buy another board as they are very expensive in the UK and I am, ahem, a student, so is there anything I can try to measure to perhaps replace any component? The smaller capacitor beside the grey socket is working fine.