Hi, I have an Arduino Mega and an Etherned Shield. Both works great together, if I have connected the board to my PC via USB cable.
But if i connect the board to my external 9V power supply just one red LED lights up on the ethernet shield. The shield does not connect to the network :/...
Can you imagine what is wrong with my board / shield?
PS: I noticed that when i use an battery pack of 4x1.5V (AA) it also works. Is it possible that 9V are too much?