Ethernet: Arduino Uno and WebClient sketch - sketch doesn't work

Hello,
Recently I bought the original Arduino Ethernet shield (R3) and wanted to test it on my Uno R3 using th WebClient sketch (which connects to Google's servers and fetch data). For some reason, it didn't work at all - no response was given to me.
Yet, when I tested the same sketch on my Mega (2560 R3) it worked flaulessly.

So my question is - why does it happen? How can I fix this? It driving me crazy >:(
Thanks,
Dan

It should work.

This WebClient ? https://www.arduino.cc/en/Tutorial/WebClient

We have to know more. Could you print a message after Serial.begin() to the serial monitor. Can you see that message ?
Do you see a message that it is connected or has failed to connect ?

What else is different ? Did you use another usb cable or other usb port for the Mega board ?

Koepel:
It should work.

This WebClient ? https://www.arduino.cc/en/Tutorial/WebClient

We have to know more. Could you print a message after Serial.begin() to the serial monitor. Can you see that message ?
Do you see a message that it is connected or has failed to connect ?

What else is different ? Did you use another usb cable or other usb port for the Mega board ?

Yes, that's the sketch..
I've used the same usb port and everything the same.. I did managed to print a message after the Serial.begin() but I didn't get any message that it connected or failed to connect, and not even a message about Ethernet.begin(mac) or Ethernet.begin(mac, ip)...

Check the ICSP pins. If they are not connecting, you will have problems.

Try this test code. If the serial monitor shows 192.168.1.2, then the SPI bus and the SPI side of the w5100 is working. If it shows anything else, like 0.0.0.0, then you have a problem on the SPI side of the ethernet shield.

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

// this must be unique
byte mac[] = {  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xEC };
IPAddress ip(192,168,1,2);

void setup() {
  Serial.begin(9600);

  // disable SD SPI while starting W5100
  pinMode(4,OUTPUT);
  digitalWrite(4,HIGH);

  // Start ethernet
  Serial.print(F("Starting ethernet..."));

  Ethernet.begin(mac,ip);

  Serial.println(Ethernet.localIP());
}

void loop() {

}

Thanks everyone, I’ve solved the problem!
The problem was that I used the provided MAC address instead of my real Ethernet Shield’s MAC address. When I changed the MAC address to the real one, it started working.

Thanks again!