How do I know my Leonardo isn't fried?
Hi everyone, I bought an Arduino Leonardo (not new) today and when I'm connecting it nothing happens. In Windows 7 x64 I couldn't find any device related. I know how things should behave (a little popup or a new device in device manager) but nothing happens. I've also tried in Linux (Ubuntu 12.04) and no /dev/ttyACM showed up.
The power led, Tx and Rx are all lit and the microcontroller gets hot in 5 - 10 seconds from when I connect the USB cable.
Is there anything I can do to recover it? Or is there any test to find if my board is fried or is just in an undefined state?
Posted Mar 12, 2013, 6:19 PM UTC
25
Have you tried a different USB port? On my laptop, one of the ports works fine, with the Leo, the others hate it. So try that first. Now when you say it gets hot... How hot are we talking? Warm or "Can't leave a finger on it for more then a second" hot? And are you talking about the microcontroller specifically?
edit: Just dug one out and plugged it in. When it's first plugged in, you should see the L LED pulse. Same thing should happen when you press the reset button.
As for heat, it really depends on what it's doing. Driving a bunch of LEDs, you'll get a little heat, doing an analog read and writing the output to the serial line... not so much. Is it just a bare board or are you driving any loads? If it's just the bare board and it's getting to hot to touch... you might have a problem.
I've tried all my USB ports on three different computers, same behavior.
I'm talking about the microcontroller specifically, it gets hot like above 60 degree Celsius (I didn't had the heart to let it connected more than that)
The LED is not pulsing, this board is second hand so I don't expect it to have the original program on it, I'm sure the former owner played with it.
Also nothing is happening when I press the reset button, even if I keep it pressed no led blinks and the microcontroller still gets hot during this time, even if I press the reset button at a rate of 4-5 per second the microcontroller gets hot. (I actually measured the time it takes to get hot and it's actually something like 18-25 seconds)
And Yes is just the bare board.
It is broken. It should never get that hot when not connected to anything external.
Maybe there is metal dust causing a short, brush it with something and/or spray compressed air at it. If that doesn't help then I actually think you have a defective unit.
Don't leave it on too long, otherwise it releases its magic smoke. It is broken probably.