arduinoSD卡模块识别不到sd卡，可能是什么原因引起的啊？

连线和代码都没问题，卡的类型和端口选择都没有问题，/*
*  Arduino SD Card Tutorial Example
*  
*  by Dejan Nedelkovski, www.HowToMechatronics.com
*/
#include <SD.h>
#include <SPI.h>
File myFile;
int pinCS = 53; // Pin 10 on Arduino Uno
void setup() {

  Serial.begin(9600);
  pinMode(pinCS, OUTPUT);

  // SD Card Initialization
  if (SD.begin())
  {
    Serial.println("SD card is ready to use.");
  } else
  {
    Serial.println("SD card initialization failed");
    return;
  }

  // Create/Open file
  myFile = SD.open("test.txt", FILE_WRITE);

  // if the file opened okay, write to it:
  if (myFile) {
    Serial.println("Writing to file...");
    // Write to file
    myFile.println("Testing text 1, 2 ,3...");
    myFile.close(); // close the file
    Serial.println("Done.");
  }
  // if the file didn't open, print an error:
  else {
    Serial.println("error opening test.txt");
  }
  // Reading the file
  myFile = SD.open("test.txt");
  if (myFile) {
    Serial.println("Read:");
    // Reading the whole file
    while (myFile.available()) {
      Serial.write(myFile.read());
   }
    myFile.close();
  }
  else {
    Serial.println("error opening test.txt");
  }

}
void loop() {
  // empty
}

选的2560板子，代码也没有问题，但是显示初始化失败是怎么回事呢