Input voltage problem

Hi everyone,

I have built a project around arduino Duemilanove with ethernet shield.
All works normally when the board is powered with usb.

The Ethernet shield does not work when the board is supplied by 12V.
The arduino regulator is very hot. The leds on the ethernet shield is blinking RX / FULLD/100M/LINK.

I have read in the documentation that we can use 12V dc supply.

Someone knows what is the problem ?

Thanks in advance.

PS : a quick patch will be to power with 5V the arduino board with usb connector

I have tried the patch : I put 5V DC between black(GND) and red (+5V) on a usb connector. It works great !

Another solution is to use 7-8V DC power supply to avoid overheating...

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1241924251

Please do a quick search before posting - glad you figured out the solution though

I'm not english speaking native so it's not always easy to find the right keywords.... It is obvious after but....

Thanks for your reply !