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2 dead Netduino go

Started by stinger151, Nov 05 2013 04:50 PM

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9 replies to this topic

#1 stinger151

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Posted 05 November 2013 - 04:50 PM

hi

my name is francesco i am an It specialist living in austria

I bought 3 netduino go�s and some nwazet hardware for testing purpose.-> Great job everyone!

Unfortunatly this weekend something bad happend:

i had to demonstrate some relay switching via xbee.

So no problem developed everything on 1 netduingo go ->everything works

deployed the files on another GO and attached it to the nwazet powersupply and here the end begins....

The GO power light goes on for some seconds and turns off. S**t 15 minutes to the presentation ->ok maybe a production error i thought (wrong as i know now) and so i deployed on GO NR.3 and fried that one too.

(i have done the presentation on netduino 1 and hidded the notebook under the table as powersource )

Today i had some time measuring and i found out that the powersupply passes 12v directly through!

So my Go�s got 12v really really bad!

The Nwazet Powerboard "Power Switch Rev.A" was never used bevor

ok the questions:)

1) any ideas why my powerboard passesthrough

2) any chance that my go(STM) survived and i can swap the power supply to bring it back to live?

3) i have a Oscilloscope and a good regulatet powersupply so if anyone can tell me were to put the voltage on i could test.

any help is appreciatet

thank you!

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#2 Chris Walker

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LocationNew York, NY

Posted 12 November 2013 - 06:00 PM

Hi stinger151, Oh no.

Electrocuting a 3.3V/5V device with 12V is no good at all.

Let's see what we can do to help, and get you back up and running. When you say that your power supply passed through 12V, what is the power supply? Is it sending that much voltage to the USB port input (which maxes out supporting around 5.5V)? The best place to start there is by using your multimeter to figure out what's wrong with it. On the Netduino Go...they can be pretty tough, but not bulletproof. If the DC-DC switch is what got electrocuted, there's a chance that you can replace those with some hand-soldering and be okay again. Check the input voltage and output voltage on the ST voltage switch; if it's not working when powered by 5V USB, then that's a good place to start if you're the adventurous-hand-soldering-type. Schematics are on the downloads page and the ST part you're looking for is the little one by the inductor. Does that help get you started? Welcome to the Netduino community, Chris

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#3 stinger151

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Posted 16 December 2013 - 12:00 PM

Hi

Thank you, for your answer!

1) the power supply used is this: http://nwazet.com/power with a 12v wall plug. Maybe I will dump (to risky)

2) I will have a look at the voltage regulator tonight and post my results. but I think I will buy 2 new netduino go (I switched to netduino go because I didn't want to go on new adventurous-hand-soldering-mission�s ....)

Thank you for your support.

Br Francesco

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#4 neslekkim

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LocationOslo, Norway

Posted 16 December 2013 - 12:06 PM

Did that poweradapter really send 12v out of the usb connector??? I have used mine without problems..

--
Asbj�rn

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#5 stinger151

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Posted 16 December 2013 - 03:50 PM

hi

Yes it does! i couldn�t believe it to.

i have 2 of them and BOTH of them just passes the voltage.

here a picture of the measurement (12V netgeat wallplug-> Nwazet PS-> Usb-Cabel-DMM)

Posted Image

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#6 CW2

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LocationCzech Republic

Posted 16 December 2013 - 07:33 PM

here a picture of the measurement (12V netgeat wallplug-> Nwazet PS-> Usb-Cabel-DMM)

Could you please check the wallplug barrel jack polarity? Does it have positive voltage at the center?

Also, is it DC?

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#7 stinger151

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Posted 16 December 2013 - 07:48 PM

Sure 12 V 1A and center positive (measured). i tried different ones....

it�s a

Netgear

Model: t012he1209

br

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#8 CW2

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Posted 16 December 2013 - 08:22 PM

Ok, thanks. So, the power module seems to be faulty? It should not be hard to verify that, it is just MC33269 linear regulator, measure voltage on its pads... Although personally, I am a little bit surprised, those linear regulators have thermal and short circuit protection. Is it getting hot? Or perhaps there is something wrong on the PCB?