Unable to acess SERVER without USB Cable Connected

I am unable to access the web server unless I plugin the the USB Cable . The USB cable wants to be connected to any USB port. Ir-respective weather the drivers are installed or not.As long as the USB is plugged in I can access the server.

I power the board using a 9V DC transformer and the RJ45 hooks to the Ethernet shield

The board controls a relay.Weather or not the USB cable is plugged in the Relay operation is as per logic

#include <SPI.h>
#include <Ethernet.h>

byte mac = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED}; //MAC ADDRESS
IPAddress ip(192, 168, 1, 177); //STATIC LAN IP ADDRESS
EthernetServer server(1410); //----->>SERVER PORT<<--------

void setup()
{
pinMode(7,OUTPUT);
pinMode(6,INPUT);
pinMode(13,OUTPUT);

Serial.begin(9600);
Ethernet.begin(mac, ip);
server.begin();
}

void loop()
{

EthernetClient client = server.available();
if (client)
{

if(Serial) Serial.println(“Ethernet Connected”);

**some html… some functions & reading of pins all are working alright and some logic… **

}
}

}

As long as the USB is plugged in I can access the server.

So, as long as the Arduino is getting sufficient power, everything works. Without the power from the USB cable, stuff doesn't work. Well, hello, that looks like a clue.

I power the board using a 9V DC transformer

But what color is it? The important thing is the amperage!

The 9V DC supply is rated at 500ma ... doesn't look like the trouble... or could it be

doesn't look like the trouble... or could it be

For a shield that can draw 2A? Nah, that can't be the problem.

;D

I measured the Voltage on the Power supply under load... 4.5Veeee ... :D naah.. The power supply wasnt the problem ;)

PaulS ... Cheers....

The power supply wasnt the problem

So, what was?

:) :) The Ethernet shield was... It was drawing too much power... :smiling_imp: