AD2 over voltage :-(

[peter taylor]

Managed to see a spike that fried something next to the usb port. What was this SMD part? 

I know there is minimal chance it's coming back to life, but i'd like to try. Was that a resistor? What value?

 

 

EDIT:

Thinking about it further, it think it was a ground loop, not over-voltage, since the voltage should have been ~30v but with the 10x probe this should have been well below the limit. Anyhow, lesson learned, but i'd love to get a spec to replace the component. 

[attila]

Hi @peter taylor

This was a ferrite between the Analog Discovery and USB ground. Supposed to filter noise from USB cable/PC which acted as a fuse...

You can solder a simple short instead this ferrite. Hopefully only this was damaged.

Be careful. The devices and circuits should have the same ground. The AD ground is connected to the PC ground over the USB cable.

 

[peter taylor]

On 11/9/2018 at 4:02 AM, attila said:

Hi @peter taylor

This was a ferrite between the Analog Discovery and USB ground. Supposed to filter noise from USB cable/PC which acted as a fuse...

You can solder a simple short instead this ferrite. Hopefully only this was damaged.

Be careful. The devices and circuits should have the same ground. The AD ground is connected to the PC ground over the USB cable.

 

Looks like the left pad on the pcb has delaminated due to the heat.  Is the left side in my image on the USB connected side, or the AD2 side? Is there anywhere else i can use instead of that pad for a new fuse/short? Surely i can jump from somewhere else safely...

I really appreciate the help. If i'd stopped to think for just a couple more seconds... i'm a rookie with oscilloscopes, but absolutely understand my mistake. Embarrassing, honestly. 

[attila]

Hi @peter taylor

Here you have some layouts, flipped for normal viewing. I hope it helps.
The ferrite is intended for noise filtering from PC but you can replace it with a wire.

Bottom USB GND: 

Bottom device GND:

Top USB GND:

Top device GND:

[peter taylor]

Thanks, that did help with attempting a rescue. She's dead though. A ten pin chip next to the barrel jack on the top side is also fried. What else? Who knows. 

Any chance i can get a sweet deal on a replacement? I know it's definitely not warranty, since i was a dummy, but I'm a poor student and hobbyist, and i didn't get more than a couple hours out of this one :-/ I understand if not. 

Thanks for your help, i really appreciate it!

Peter