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Topic: Arduino Nano and short circuits (Read 3 times) previous topic - next topic

jet

In the past ~3 years, I've done a number of projects using Arduino of various kinds and helped in a few classes where many students were using Arduino for the first time and I've only seen one or two Arduino boards killed by a temporary short.

In the past month, I've fried two Nano v3.0 with brief shorts due to a loose wire.   Each time, the same SMT component smoked:
http://www.flickr.com/photos/allartburns/4225076075/

Are the Nano V3's especially fragile, or am I just unlucky?

retrolefty

Quote
Are the Nano V3's especially fragile, or am I just unlucky?


I would say it looks like the Nano is a more fragile design. The standard Arduino board uses a thermofuse to limit current from the USB port to 500ma and resets automaticaly when the short is removed. On the Nano there doesn't appear to be a thermofuse installed. The burned component looks to me to be the D1 isolation diode. It's used to 'switch' the +5vdc source from either the USB power source or the on-board +5vdc regulator and allows whatever source has the higher voltage to supply the boards current. The parts list shows it as a 500ma diode, so most likely a careless wire could cause a short circuit and is burning the diode open.
Just a guess as I don't have the Eagle program installed to actually see if that component is D1 or not.

Lefty

jet

Thanks -- I was trying to decipher the Eagle pcb layout and getting nowhere.

So in there, I should be able to replace this with an SMT rework station and a steady hand?  I picked up a cheap refurb lately, this seems like a good thing to practice on.

Gravitech

#3
Jan 03, 2010, 01:26 pm Last Edit: Jan 03, 2010, 01:26 pm by coolguy Reason: 1
Or better yet, just contact us to get a RMA# and you can send them back for a free repair! support@gravitech.us

Happy Nano!

drh

Is Gravitech the manufacturer of the Nanos? I've fried a couple as well and would like to be able to return them for repair.

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