sd shield for arduino mega

hey guys i have question
Someone once worked with "CTE TFT LCD / SD Card Shield For Arduino MEGA2560 With 5V To 3.3V Level Translation IC"

until now i used arduino uno with simple shield
but now i work with mega2560 and for some reasons i cant make it work
can you please help me understand whats wrong?
thanks in advance

here the code i used for uno and his shield

#include<SPI.h>
#include<SD.h>
File MyFile;
String JDAMmsg = "";
String indexMsg = "";
bool isLoop = false;
int cntLoop = 0;
int numLoop = 2000;
void setup()
{
  Serial.begin(9600);
  while (!Serial) {
    ;
  }
  pinMode(4, OUTPUT);
  if (!SD.begin(4))

  {
    while (1);
  }
}
void loop()
{
  MyFile = SD.open("dalg122.txt");
  while (Serial.available() > 0 && !isLoop)               //check if the serial is available and if isLoop is true
  {
    char data = char (Serial.read());                     //read one char every time
    JDAMmsg += data;                                      //add the char to one string
    cntLoop++;                                            //counter rise up by one
    if (cntLoop > numLoop)                                //check if it is under 2000 chars cuz the jdam print infinty information
      isLoop = true;                                      //keep the while work
  }
  MyFile.close();
  Serial.print(JDAMmsg);
}

i forgot..
this is the link to the shield:

MEGA_Shield_schematic.pdf (18.6 KB)

Try with SD.begin(34) in your code, pin 34 is where the SD card CS signal is connected to. Also check JP9 on the board, should be closed to enable SD card.

Ciao, Ale.

ilguargua:
Try with SD.begin(34) in your code, pin 34 is where the SD card CS signal is connected to. Also check JP9 on the board, should be closed to enable SD card.

Ciao, Ale.

thanks