DC supply problems. Faulty board?

Hi all,

I've just begun playing with the Arduino Due after quite a bit of experience with the Uno and Pro Mini, and either there's something very different about the Due or I have a faulty board.

Basically, I've tried using a 12V DC plug-pack with a center positive output and am getting nothing from the Due -- no power LED, and no flashing pin 13 LED (I am, of course, running "flash" just to get started).

The board works fine as long as it draws power from the USB connection, but the moment I disconnect USB it goes dead.

The only further info I can give is that when I have the board connected only to the plug-pack the 5V rail reads 2.6V and the 3.3V rail reads 1.7V. Connect the USB and they immediately jump to 5.15V and 3.5V respectively.

I'm not sure if this indicates a fault with the board, or with my expectation that the Due should function just as the Uno does (namely, connect an external supply and the board boots and runs the loaded sketch).

Do you get 12V from the supply when it's plugged into the Due or is it dropping?

The supply voltage remains constant at 13.3 whether connected to the Due or not.

It does sound like there's an issue with the board, are you able to determine if the 13.3v reaches the input of the 5v regulator?

Yes and yes!

I was able to check the input to the 5v reg. and it's sitting at 13.3 V with the DC supply connected.

Sounds like the regulator is busted :frowning:

Hmmm... Not what I wanted to hear! :D

I might try replacing it -- I've never tried replacing SMT packages before but I guess there's nothing to loose.

Thanks for taking the time to respond. I appreciate it.