No power from power jack


Another strange problem. I can't power the Arduino using the power jack. I can using the USB cable.

I tried many different external transfo, but not success

I did removed everything, leaving only the Arduino.

I there a fuse that could be blow?



I did found a 7.2 v transfo and it power up the Arduino. I tried many 9v and 12v that was not working with the unit.

The ones that didn't work probably had a 2.5mm plug, which will fit into the barrel jack on the Arduino but won't make an electrical connection because the internal pin is a different size.

I'm having a weird and similar problem...I have a 9v power supply that I'm trying to use with a brand new Due board.

The board works fine when I use the USB power supply.

But when I plug in the 9 volt barrel connector the Due loses power.

When I test the voltage at the VIN pin it shows 9 volts (so clearly the 9 volt power is getting through ok). The 5 volt pin measures at 1.23 volts and the 3.3 volt pin measures at 0.45 volts.

With reference to BJHenry's post above I tried two different sized barrel connectors on different power supplies with no difference to the results.

As an aside, I tried to find the 9-12 to 5 volt regulator on the board. From the schematic ( I was looking for IC2 - an LM2734Y but I couldn't find it on this layout ( I would have expected it to be a fairly large device like the 5 to 3.3 volts regulator IC4 which is a NCP1117ST33T3G. However, I think I must have a later revision board because my Due (an original) has a different layout and seems to have a large device next to IC4 doing the 12 volt regulation. I am currently wondering if it's working properly???