Arduino mega kills lsptop

Development Tools IDE 1.x
1

I have an Arduino Mega hooked up to a number off accessories. The mega runs on a12v DC supply. All has worked well until weekend. I was testing a sketch and all the sudden my laptop died. The laptop was a Leveno (with a 4 year warranty, thank goodness). I in plugged in my old HP pavilion and the same thing happened. The computer will not turn on, even when reset. The Hp the fan runs, but I cannot turn it off with the power button.

Any suggestions? I don’t mind buying a new mega if I make a mistake, but laptops are a little more expensive.

2

Turn off everything on both laptops and take out the battery for at least 10 minutes on both lappies.

Disconnect EVERYTHING from the mega as it sounds like to have either killed it or something connected to it is causing the problem.

Re-start each laptop and check that your USB ports are working.

Now connect just the mega !

Does it still cause a laptop to fail ?
If so the mega is dead with something quite serious.

Now we need a schematic of your circuits (hand drawn will be fine)

Could you also take a few moments to Learn How To Use The Forum.

Other general help and troubleshooting advice can be found here.
It will help you get the best out of the forum in the future.

3

Did some testing and it is an an over voltage condition. The Arduino Mega is measuring 10 volts at the USB cable to the computer. Should only be 5 volts. That would explain why the computer died. Now I need to replace the mega and and figure out why the mega went crazy. I am awaiting a usb isolator to control the voltage from the mega.

Thanks for Your suggestions. Headed me in the right direction.

4

Wonder if you connected the 12v supply the wrong way around ?