¿No se pueden escribir datos para 24c256 eeprom?

Estoy usando el microcontrolador Pic24fj128ga202 y 24c256 eeprom y ISL1208 RTC que se interconecta a través del bus I2c. El problema es que puedo leer y escribir los datos en eeprom y RTC, pero en otras placas (con el mismo diseño) no puedo leer ni escribir los datos a través del bus i2c. He publicado mi código y el esquema también amablemente alguien me dirija ¿cuál es el problema? No tengo osciloscopio para verificar esto.

#include <stdio.h>
#include "C:\Program Files\Microchip\xc16\v1.24\support\PIC24F\h\p24FJ128GA202.h"
#include "uart.h"
// calculate baud rate of I2C
#define Fosc      32000000
#define Fcy       (Fosc/2)
#define Fsck      400000
#define I2C_BRG  ((Fcy/2/Fsck)-1)

int main()
{
    InitProcessor();
    Delayms();
    while(1)
    {
        I2c_Write(0xA0,1,'A');
        Delayms(5000);
        uart1tx(I2C_read(0xA0,1));
    }
}

void InitProcessor(void)
{
    // Oscillator    8mhz no pll
    OSCCON = 0x0011;
    CLKDIV = 0x0000; 

    // Configure Digital pins
    ANSA = 0x0003;
    ANSB = 0x0000;

    //  Assign  IO values for Ports
    PORTA = 0x0000;
    TRISA = 0x001B;
    TRISB = 0x468f;                   // 7 as receive and 8 as transmitter
    //PORTB = 0x0000;


    // Interrupt Bits 
    INTCON1 = 0x0000;                                               // Disable  Interrupts
    INTCON2 = 0x0000;

    // Init I2C
    I2C2CONL = 0x8000;
    I2C2CONH = 0x0000;
    I2C2STAT = 0x0000;
    I2C2BRG = I2C_BRG;
    //I2C2BRG = 79;

    Delayms(1000);
    Init_rtc();
}

void Init_rtc()
{
    I2c_Write(0xde, 0x07, 0x10);
    I2c_Write(0xde, 0x06, 0x00);
    Delayms(20);
}

void I2c_Write(unsigned char DeviceAddress,unsigned int Addr,unsigned char i2c_value)
{
    unsigned char i2c_exit=1,i2c_write=0;
    int I2creg = 0;
    IFS3 &= ~0x0004;
    I2C2CONL |= 0x0001;
    I2cTimer = 0;
    while(i2c_exit)
    {
        if(I2cTimer > 30){                                              // Exit routine
            i2c_exit = 0;
        }
        if(IFS3& 0x0004)
        {
            IFS3 &= ~0x0004;
            I2cTimer = 0;
            if(i2c_write == 0)
            {
                I2C2TRN = (DeviceAddress & 0xfe);
                if(DeviceAddress == 0xde)
                    i2c_write = 1;
            }
            else if(i2c_write == 1)
                I2C2TRN = Addr >> 8;
            else if(i2c_write == 2)
                I2C2TRN = Addr & 0xFF;
            else if(i2c_write == 3)
                I2C2TRN = i2c_value;
            else if(i2c_write == 4)
                I2C2CONL |= 0x04;
            else
            {
                i2c_write = 100;
                i2c_exit = 0;
            }
            i2c_write++;
        }
    }
    Delayms(5);
}

/* Function to Read and return a data through I2C  */
unsigned char I2C_read(unsigned char DeviceAddress,unsigned int Addr)
{   unsigned char db, ReadState=0,I2CFlag;
    ReadState = 0;
    IFS3 &= ~0x0004;                                                        // Master I2C interrupt flag
    I2CFlag = 1;
    I2C2CONL |= 0x0001;         // SEN = 1;
    I2cTimer = 0;
    while(I2CFlag){
        if(I2cTimer > 30){                                              // Exit routine
            I2CFlag = 0;

            //ModemDiagnostics(64,1);
        }
        //uart1tx('r');
        if(IFS3 & 0x0004)
        {       
            I2cTimer = 0;
            IFS3 &= ~0x0004;
            if(ReadState == 0)
            {
                I2C2TRN = (DeviceAddress & 0xfe);
                if(DeviceAddress == 0xde)
                    ReadState = 1;
            }
            else if(ReadState == 1)
                I2C2TRN = Addr >> 8;
            else if(ReadState == 2)
                I2C2TRN = Addr & 0xff;
            else if(ReadState == 3)I2C2CONL |= 0x0002;  
            else if(ReadState == 4)I2C2TRN = (DeviceAddress | 0x01);
            else if(ReadState == 5){
                I2C2CONL |= 0x0008;                             // RCEN = 1, Enable data receive
                db = I2C2RCV;
            }
            else if(ReadState == 6){
                db = I2C2RCV;                                                       // Read Data
                I2C2CONL |= 0x0020;                                                 // ACKDT = 1, Set Acknowledge bit (No Acknowledge)
                Delayms(5);
                I2C2CONL |= 0x0010;                                                 // ACKEN = 1
            }
            else if(ReadState == 7)I2C2CONL |= 0x04;                                // PEN = 1, Stop enable bit forI2C
            else{ReadState = 100; I2CFlag = 0;}                                     
            ReadState++;
        }
    }
    if(db)
        return db;
    else
        return 0;
}