Mistery: I2C not working, blink working

Using Arduino Networking, Protocols, and Devices
8

As requested:
Uno connection:

800×602 134 KB

Mega connection:

800×602 92.1 KB

Main code:

#include <Wire.h>
#include <L3G.h>

L3G gyro;

void setup() {
  Serial.begin(9600);
  Wire.begin();
  
  if (!gyro.init())
  {
    Serial.println("Failed to autodetect gyro type!");
    while (1);
  }

  gyro.enableDefault();
}

void loop() {
  gyro.read();

  Serial.print("G ");
  Serial.print("X: ");
  Serial.print((int)gyro.g.x);
  Serial.print(" Y: ");
  Serial.print((int)gyro.g.y);
  Serial.print(" Z: ");
  Serial.println((int)gyro.g.z);

  delay(100);
}

Library: GitHub - pololu/l3g-arduino: Arduino library for Pololu L3G4200D and L3GD20 boards