MX 28 arduino - Issue after writting

Hello everyone, I am working with MX 28 motor and a arduino. I made a mistake I write a two bytes in a one byte register and I am no more able to drive it correctly. I use the second function instead of the first one :

/* Set the value of a single-byte register. */
void ax12SetRegister(int id, int regstart, int data){
    setTX(id);    
    int checksum = ~((id + 4 + AX_WRITE_DATA + regstart + (data&0xff)) % 256);
    ax12writeB(0xFF);
    ax12writeB(0xFF);
    ax12writeB(id);
    ax12writeB(4);    // length
    ax12writeB(AX_WRITE_DATA);
    ax12writeB(regstart);
    ax12writeB(data&0xff);
    // checksum = 
    ax12writeB(checksum);
    setRX(id);
    //ax12ReadPacket();
}
/* Set the value of a double-byte register. */
void ax12SetRegister2(int id, int regstart, int data){
    setTX(id);    
    int checksum = ~((id + 5 + AX_WRITE_DATA + regstart + (data&0xFF) + ((data&0xFF00)>>8)) % 256);
    ax12writeB(0xFF);
    ax12writeB(0xFF);
    ax12writeB(id);
    ax12writeB(5);    // length
    ax12writeB(AX_WRITE_DATA);
    ax12writeB(regstart);
    ax12writeB(data&0xff);
    ax12writeB((data&0xff00)>>8);
    // checksum = 
    ax12writeB(checksum);
    setRX(id);
    //ax12ReadPacket();
}

I tried to drive my MX28 with the id 254 but even so I have no result. Is it possible that I changed the baud rate by mistake ? How an I make a quick check about that ? Is that possible to reset the eeprom data by default ?

Thank you.

You are assuming you will attract the attention of someone who knows what an MX28 is and who knows what the cryptic things like ax12writeB(0xFF); do.

...R