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Author Topic: No Power to the Arduino Uno Board  (Read 492 times)
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I bought a 12VDC 1A wall wart and when I plug it into my Arduino I dont get any power.

What am I doing wrong????
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Is it plugged into the wall?

If you use a multimeter, do you measure 12V at the output of the barrel jack on the board? Work your way down the power chain.
http://arduino.cc/en/uploads/Main/Arduino_Uno_Rev3-schematic.pdf
The barrel jack & 5V regulator are at the top-right of the schematic,
and lower left in the picture.
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I bought a 12VDC 1A wall wart and when I plug it into my Arduino I dont get any power.

What am I doing wrong????

Is your wall wart of the proper DC polarity, that is outside shell negative, center positive? The arduino has a polarity protection series diode wired in the external power path that will prevent damage to the board if your wall wart is of the wrong polarity, but it will of course not work until you can reverse the polarity if you can.

Lefty
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oh oh is it a barrel jack with the V and ground inverted around ?
some have the inner core - some have it +
so check with meter
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